fuelpump

Fuel Pump Access, Replacement and Rebuilding
(Classic Range Rovers)

Introduction: Design and Failure Modes
Access: OEM and Owner-Cut Access Hatches
Accessing Fuel Pump by Removing Loadspace Floor
Accessing Pump by Official Method Without Hatch
Fuel Pump Removal from Tank
Dismantling the Pump Assembly
Fuel Pump Rebuild
Fuel Level Sender Problems and Solutions
Related Links

Photo: Fuel pump access hatch in loadspace floor of late 1990-and-up Range Rover

Introduction: Design and Failure Modes

The Range Rover's fuel pump is mounted inside the tank, through a hole in its top. It is mounted in a special collapsible intake assembly to allow it to keep on operating when the bottom of the tank is deformed by hitting rocks and other terrain obstacles. However, failure of the fuel pump due to various causes is the most common reason for a Range Rover to be towed into a shop. The most frequent failure modes are:

Wires and Epoxy at Top of Pump: Kevin Kelly reports that his mechanic Philippe at Roverland finds that the most common reason the pumps stop working is the disintegration of the epoxy and electrical connections where the wires connect to the top of the pump, leaving no solder holding the wires in. As the pumps get older they run hotter and most seem to die when the wire at the top of the pump gets so hot that it burns out and disconnects from the pump. Many towed Range Rovers could have been driven home if the owners had pulled the fuel pump access panel in the loadspace area of 91 and up models, and spliced the wires back on.

Blocked Vacuum Relief/Rollover Valve: Another common reason for failure is a blocked vacuum relief/rollover valve in the evaporation tank in the rear quarter panel. The vacuum buildup causes the tank to collapse and crush the fuel pump. Initial symptoms are often a temporary cutout of the engine at high speed, progressing to a permanent failure. Loosening the gas cap to relieve the vacuum can often get you home in this case.

Brushes Worn Out: The natural life of the pump is somewhere around 100,000 miles, at which point the carbon brushes wear down to nothing, so it needs to be replaced long before the other vital components of the vehicle wear out. Later Classics (about 1991 onwards) have a removeable plate in the floor of the loadspace above the fuel tank, allowing the fuel pump to be removed without the tedious procedure of draining and dropping the tank as required on earlier models.

Relay, Fuse or Inertia Switch Failure: You can check to see if power is getting to the readily accessible fuel pump connector which sits on the frame rail behind the left rear tire. If not, the fuse, relay or inertia switch (which shuts off the fuel pump in case of a collision) is probably to blame. The fuel pump relay, located under the rear of the front passenger seat on North American models, was observed by Kevin to be the same as the power seat relay, so if it fails you can "borrow" the latter for a temporary fix. If you do need a new fuel pump relay you can get one from Bosch (on the web at boschservice.com, with a complete listing by state of Bosch service centers). The Bosch relay number is 0332014112. The Inertia Switch is located under the back of the drivers seat and looks like a push switch, down on, up off. If you cannot get it to reconnect you can jumper it to get you home.

Access: OEM and Owner-Cut Fuel Pump Access Hatches

In late 1990, Land Rover sensibly introduced a small access hatch in the loadspace floor just above the fuel pump, greatly easing replacement and repair operations. Officially, the change happened for the 1991 model year, but Joseph Reseland reports his 1990 (VIN# SALHV1248LA441098) has the fuel pump access panel, so if yours is later than that it should have one. (If yors is earlier and has one, please email me so we can establish the starting point for tis mod). The photos below illustrate the factory access panel.


Fuel pump access plate in loadspace (late model Classics)	Top of fuel pump viewed through access plate

Dan Wagman had to change the fuel pump twice on his 1990 Range Rover, so the second time he decided to cut his own access hole in the loadspace floor to ease the job. It wasn't the easiest thing for him to do with the tank in place, trying to guess where the hatch should be cut. But now that he has done it, he knows where it is and how big it ought to be, and was kind enough to share his method with us.

Measuring for the Cut-out
The fuel pump lid is six inches long (from back of vehicle to front) and 7.5 inches wide (from left to right of vehicle). The bottom left corner is 12 inches from the edge of the bottom part of the aluminum stripping that is riveted to the vehicle (note that there is a top part as well, where you'd slide the sound proofing material between the bottom part and the top part). Once you measured 12 inches, the bottom left corner should be 16.5 inches from the indentation into the luggage compartment for the spare tire. Another way to measure where you would want to have the left bottom corner for the latch is to count eight depressions in (= 16.5 inches) (the floor isn't flat, but rather has raised and depressed lengths). It's important that you cut the 6 inch length (going from the back of the vehicle to the front) in the depressed parts of the floor as opposed to the raised parts.

For additional guidance on the best place to cut the access hatch, Jack Hall measured the exact position of the pump when he removed his cargo floor (see below). He found the distance to the center of the fuel pump is 18 1/4 inches from the left edge of the cargo floor panel and 18 1/2 inches from the bottom edge of the tailgate when it is in the down position or 14 1/2 inches from the rear edge of the floor opening.

Cutting and Sealing the Hatch
Dan used a sawzall to cut the luggage compartment floor, but you need to take care not to have the blade hit the tank and/or the fuel line and wiring from the fuel pump. When you cut the top length (7.5 inches, left to right), you get close to the hose/wires and you'll need somebody to watch from below to make sure you don't let the blade cut these components. Once the lid was removed, Dan pop riveted two 1 inch x 11 inch x 1/4 inch thick pieces of aluminum to the bottom of the compartment, at the depressed part of the floor. Then he laid the lid over the top, drilled two holes and screwed the lid to the aluminum. He used silicone sealant to seal the cut. Following this design, from now on you can access the fuel pump without having to drop the tank.

Accessing Pump by Removing Loadspace Floor

Removal of Entire Loadspace Floor:
If you have a pre-91 model Classic without the access hatch. Kevin Kelly reports that it is possible to remove the entire rear floor to get to the pump. Jack Hall has now performed this operation on his 87 RR and kindly supplied us with full details and photographs. He reports: "Removing the floor wasn't all that difficult. Basically all I did was to remove the seatbelt anchor bolts, then drill out the rivets holding down the front and rear trim strips and all the rivets around and across the floor panel. I believe it had once before been removed due to evidence of drill shavings. Once you drill out the rivets holding the seatbelt anchor plate (which is underneath the floor) they will swing away. I will probably need someone to pull the rivets while I hold them up from underneath".


Loadspace floor still in place after drilling out the rivets	Loadspace floor removed

After Jack removed the floor he did us all a public service by carefully measuring the position of the fuel pump in order to more accurately specify where the access panel should be for those wicshing to cut one. He found the distance to near the center of the fuel pump is 18 1/4 inches from the left edge of the cargo floor panel (ie the panel itself, not the opening) and 18 1/2 inches from the bottom edge of the tailgate when it is in the down position or 14 1/2 inches from the rear edge of the floor opening.

Accessing Pump by Official Method without Hatch or Floor Removal

Removal of Tank:
If you do not wish to remove the entire floor, or cut a hatch as above, fuel pump replacement necessitates resorting to the officially sanctioned method involving first removing the tank for access. John Benham reports that the typical R/R shop manual does not supply all the practical information needed for this operation, so he offers the following tips based on doing the job on his 89 model. (Prior to the job, he power sprayed underneath the rear of the R/R to rid all loose dirt and rocks). The instructions apply to all pre-access hatch models (ie pre 1991).

To drain tank, put both back tires up on 4x4 blocks. This gives enough clearance to place a jerry can upright with a large funnel under the gas tank drain. Gas
tank drain: 19mm. Spray penetrating oil on all of the hose clamps.

Right Hand Side - 7 hoses to disconnect: large filler hose, intermediate breather hose, 3 smaller evaporative loss hoses, 1- fuel supply to filter, fuel return hose
(forward of the fuel filter). The hose clamps can be awkward to remove since they are usually oriented so they were easy to assemble at the factory with free access to the top of the tank before the body was put on! NOTE: Several owners have found these hoses frozen on and/or hard to avoid destroying (due to old age) in the process of removal. It is advisable to renew the lines and clamps if possible.

Left Hand Side - disconnect two wire assemblies: fuel pump wiring plug and the two spade connector wires for the fuel gauge sending unit.

Forward tank nuts: 17mm Rear tank nuts: 13mm Slide tank forward and down on the left side to remove. Jeff Kessler found it not quite that easy when he did it -- the inlet pipe got snagged and the tank itself caught on the braces for the trailer hitch receiver, so it required some jiggling to remove (lowering the left side first as above seems to be the secret). Rovers North recommends removing the bolts for the rear lashing rings to create more clearance.

Remove the fuel pump from the tank; see "Removing the Fuel Pump from the Tank".

Tape all hose inlets and power spray the tank and tank guard. You are now ready to remove the pump/sender assembly from the tank.

Side Job: Restoring Original Shape of Fuel Tank:
John notes that R/R fuel vent systems tend to fail causing excessive vacuum - eventually collapsing the fuel tank (see Failure Modes above). He suggests that if you have removed the fuel tank, now is a good time to pop it back into its normal shape. His procedure is to close all vents on it (turning and connecting the hoses and vents onto each other), and seal the large intake opening with tape. Leave old fuel pump in tank. With one intake hose open, blow compressed air into tank to pop it back out to normal shape.

Removing the Fuel Pump/Sender Assembly from the Tank

Be sure to follow the instructions and precautions in the shop manual when removing the pump. Note that a special tool is sold by Rover for removing the large (6"diameter) plastic ring cover cap of the fuel pump (see photo of top of pump, above). However, Jack Sullivan found a huge pair of adjustable pliers did the job, and tightened it back up too. It crushed the tabs on top a little, but other than that, it created no problem. A person could make a "special tool" to remove the cap---the Rover "special tool" is pictured in the factory workshop manual, shown grasping the ring cover cap. Michael Slade reports that to get the retaining ring off, he uses the biggest set of channel locks he can find (NAPA), then on the one end put on a Crescent wrench. Turning slowly he can get it off without snapping any of those tiny tabs. When R.J. Galati did this operation on his 94 RR, he was able to loosen the plastic ring with a gentle tapping of the ring teeth with hammer and screwdriver. He observes that there is a black rubber seal that wraps around the top (exposed portion) of the unit. It should be peeled off and placed around the hole leading to the fuel tank before reinserting the fuel pump (this makes it very much easier to get a snug fit before screwing the ring back on).

Greg Olma adds the following details: "My 89RR has a screw down top plate. Five phillips screws that were too rusted to remove with a screw driver. I used a vice grip to spin 'em. I replaced them with hex head machine screws. I have worked on Fords that have the retaining ring. I usually soak the ring with penetrant and use a big flat screwdiver and a hammer and tap the tabs on the ring around to the slot."

Dismantling The Pump/Sender Assembly

If you are replacing your pump with the genuine part, it comes as a complete assembly which can be simply inserted straight into the tank. If you are replacing yours with a low cost generic unit, or rebuilding the old one, the pump container and sender assembly is re-used and only the pump itself is replaced; in order to accomplish this the in-tank assembly must be dismantled. Jack Sullivan offers the following advice on this operation.

With the fuel pump/sender assembly removed, you will see the separate (but attached) float on a steel wire, extending out from the pump body itself. Use caution to protect the float and connecting wire, so it doesn't get bent or broken, while working on your pump. At the base of the pump, you will see a flesh colored small cylindrical container about 4 inches in diameter, with tabs at the top. Push these tabs in, and remove the cylindrical container. Inside the container, you will find the electrical pump, nylon filter bags hanging from bottom, with DC motor at top. This integral unit is mostly aluminum, about 1 1/2 inch diameter, with plastic at top, with rubber hose attached to that top. The rubber hose has a plastic hose clamp, crimping the hose to the output of the pump. Cut off that hose clamp. (When you reassemble, replace the cut off hose clamp with a standard stainless steel small hose clamp available at auto/hardware store).

Disassembled fuel pump/sender assembly. Cylindrical fuel pump container is at left (pump motor has been removed). Collapsible mounting mechanism attached to tank top lid at right.

For more detailed pictures of a very similar fuel pump assembly see the 4.0/4.6 Fuel Pump Replacement Page.

With the hose clamp cut, and the rubber hose pulled off, remove the two electrical wires attached with wire terminals to the pump motor, one is red, and one is black. Once you get the pump body out, you will notice that one wire terminal is clearly marked +, so you will have no trouble installing it correctly once you reassemble. Put the red wire on the + terminal, and the black on the other. Now, with the wires and hose off, take the cylindrical pump/motor out of the unit, so you can replace it or rebuild it by putting new brushes in it.

Installing a new Fuel Pump

The Range Rover Parts Sources page lists a number of options for generic replacement fuel pumps that are much less expensive than the genuine unit. The illustrations on this page come from R.J. Galati who replaced his worn out pump with a generic equivalent, the Borg Warner P39 (pictured below), purchased at PepBoys for $70. He says it is listed as a Chevy part on their system and has metal impellor blades versus plastic found on the original. The only real adjustment was in the electrical - Positive and Negative contacts are reversed in blade size requiring me to use the wiring included in the Borg Warner kit. He recommends replacing the black rubber seal that wraps around the top (exposed portion) of the original fuel pump unit hole leading to the fuel tank before reinserting the fuel pump (this makes it very much easier to get a snug fit before screwing the ring back on). Place a little sealant on the cork gasket and reinstall the fuel pump assembly into the tank, reversing the order of the removal operation.


RJ's original fuel pump removed (Broken piece from trying to remove brushes)	RJ's New Borg Warner P39 pump

As noted in the Range Rover Parts Sources page, NAPA P74006 for $67. with STS-2 strainer for $5 is another direct replacement. John Benham chose this one for his installation; he notes that the original two wires must be cut, soldered and heat shrunk with the new supplied wires. NOTE: Polarity is not given on new pump. It is the same as the old pump.

Greg Olma describes his experience installing another equivalent listed on the Range Rover Parts Sources page, the Airtex 3240 -- also sold under other brand names with the same 3240 part number. (Greg had already rebuilt his old pump once using the instructions below on this page, but it finally quit for good). He found the 3240 came with all the wiring and clips you need for GM installations. Since the pump on the RR uses spade connectors, one could splice in the new connectors easily. Greg did this right on the truck floor with the wiring still attached. He used crimp on wire splices, instead of solder. (He was very glad that he had cut the access hole in the floor as described above so he could get to the tank so easily). He had an unrelated problem with a loose plug that connects into the top plate -- it worked loose and disconnected. The plastic nubs that lock the male side into the fenale were a bit worn and failed to work as intended. Greg snugged a small hose clamp around the connector to prevent this in the future.

Note that some pumps have some kind of RF choke arrangement on each of the two leads before they exit the tank; Gary Hallmark reports that one of his needed replacing but has ebneen unable to find out from wither supliers or Land Rover what they are or where to get them. One shop told hin he could just rreplace the pump without them and that the later pumps don't need them. If you find out anything about them please email me.

Fuel Pump Rebuild

An alternative to replacement is rebuilding the pump. Jack Sullivan has done rebuilds of two Range Rover fuel pumps, installing new brushes in each, and testing them. Prior to this, they had 125,000 to 145000 miles on each, but now he says they work as well as ever. The brushes cost only $2.25 for the set of two, compared to buying a new fuel pump that costs around $300. Jack was kind enough to contribute the following instructions for the job. This description is for 1991 and up Classic Range Rover fuel pumps that install through an opening inside the rear floor, obviating the need to remove the fuel tank to replace the pump.

Parts Required
Jack discovered that usually, even on pumps that have considerable use and failed after 125,000 to 150,000 miles, the only thing that has worn out on them are the brushes, as found on any DC electrical motor. Thus, you can rebuild your fuel pump, by installing new brushes, and it should last another 100,000 or more miles. [It would be worth checking to make sure the bearings are in good shape before re-using the old motor -- JAB].

The brushes are approx. 1/4 square, but are tapered on one side, and are available at hobby/hardware stores for only a few dollars. (Greg Olma did the rebuild following these instructions and found an auto electric shop that sold him four brushes for a buck US$!! He filed two down to fit as instructed below).

Jack found that the Master FS3 screen sold at Autozone for $6 is nearly the exact replacement.After you take the short old ones out of your fuel pump, take them to the store to use for size comparisons, so you can match them with new ones of correct diameter. You probably won't find the taper on any new ones, so you will have to buy square ones, and taper them carefully with a fine tooth file, to approximate the shape of the removed old ones. This is easily done, taking only a few minutes, because the carbon of the new brushes files away quite quickly. So quickly, that you must be careful to not over do it.

Removing the Fuel Pump and Dismantling the Assembly:
Since the pump mechanism has to be re-used, be sure to follow the instructions and precautions in the shop manual when removing it from the tank. See the section on "Removing the Fuel Pump from the Tank" above. Then, separate the actual pump itself from the sender unit using the instructions above under "Dismantling the Pump/Sender Assembly".

Brush Replacement
At the top of the pump itself, where the wires and the hose attached, you will find a flesh colored plastic "lid" that covers the top of the unit. It has two brass terminals near the electrical terminals, and these brass terminals are the top connecting sections for the brushes. That "lid" is simply held in place by pressure tabs, so pry it, carefully, off the top of the pump/motor unit. Greg Olma advises us to be very careful while prying this off -- the brass plugs on the end are the brush caps and are friction fit into the bores. You can crack the top fairly easily.

When you get it free, you will notice two brushes, with springs that go down through holes into the motor/pump unit. Take note of the length of those brushes, and save them for reference when you go to store to find replacements (naturally, new ones will be longer than your old worn ones---no doubt the only reason your pump doesn't work). Note too, that the brushes are tapered on one side, in order to fit into the holes properly. As mentioned above, you will have to taper one side of square brushes you buy, until they match the shape of the old brushes, and fit nicely into the holes in the pump/motor unit. Be sure the brushes fit well, slide up and down in the holes and that they don't stick, or hang up, or they will not reach the armature area to make contact and work. This may sound complex and perhaps difficult, but it is not, and it takes only a few minutes to shape square brushes, and fit them---you will be pleased with the results.

The new brushes need to be soldered in place, but that is no problem, if done correctly. Use a standard soldering gun or iron, available from Radio Shack and elsewhere, and "radio" solder with ROSIN FLUX (NEVER EVER USE ACID FLUX FOR ELECTRICAL WORK SUCH AS THIS), also available at Radio Shack. Just solder in the leads on the new brushes, as the old original leads were, and the problem is solved.

Testing and Reassembly
Once brushes are installed, test the unit prior to putting the pump/motor back into main unit, by hooking up 12 volts to the electrical contacts, observing +, positive, red, and black the other terminal. The thing should run, and you can clearly hear it running. Now, install the pump/motor back into the main unit, fitting the two rubber "feet" at the base of the pump/motor into the slots for them, inside that flesh colored cylindrical container, hook up the rubber gasoline hose, with new hose clamp, push the container so tabs at top will click in place, holding the thing together. Test, with 12 V battery a final time, to see unit is still running, and presto, you have a good working fuel pump, original equipment for Range Rover, and it cost you only about $2.50.

Fuel Level Sender Problems and Solutions

David Gomes, like many other owners, experienced the frustrating problem of the fuel gauge indicator not reaching the "full" mark when the tank was full. He kindly shares the following information he obtained while researching the problem.

The pump/sender unit (PSU) is collapsible (as described above), and spring loaded so, depending on your tank, the top of the pump can be closer or farther from the bottom of the tank. The pivot for the sender arm is in the bottom section of the PSU, SO, if you push the bottom center of the tank upward, you'll effectively leave less room for the sender arm to rise. Similarly, if the base of the PSU doesn't seat fully against the bottom of the tank, you'll get the effect of a low reading when full, and lots of extra reserve at the bottom as the pump base with the pivot will be displaced upward in the tank volume.

There are 2 different kinds of direct replacement pumps for Classics, reflecting the tank design change in 1991. The older one that Dave used has a zinc chromate finished metal top piece in the tank opening, and it connects to the harness with a 3-prong plug, +,- for the pump, and one wire to the sender. A separate ground wire from the harness attaches to a tab on the metal top of the pump. The second pump, used in the later Classics, has a plastic upper portion, and connects using a 4 prong plug, +,- for the pump and for the sender. Dave heard from a mechanic that this later version NEVER reads full when first installed in an older model Classic. He is not sure if it's due to the design of the resistor (you never use all of the resistor even when the arm is against the upward stop on the PSU) or due to the way the system is grounded in the adapter harness that mates the 4-way pump socket to the 3-way plus ground setup of the old style classic wiring harness.

Dave recommends "If I had one of those plastic top pumps, I'd pull it out of the tank, and see if the gauge goes all the way up when you fully raise the arm. It DOES do so when I perform this test on my metal-top pump. If it doesn't, you may be out of options if the problem is in the design of the pump. BUT before giving up all hope, look at the wiring on the pump, and identify the two ground wires. Splice into the harness and take each of these to a definite good ground. If the sender is trying to use the same ground the pump is, it might not be good enough to provide a true zero potential".

Dave found that in his case, after he dropped the tank and re-routed the hoses that he found were in the way of the float arm, he can now get the needle to just touch the white after the gas station pump shuts off. The weird thing was that the resistor on the side of his pump showed wear marks where it was going all the way up at one time, and then shows heavier wear going only about 3/4 the way to the top of the resistor. Therefore he thinks it's still not rising as far as it should, but hasn't had the ambition to dig into it again yet. If you have further insights into this problem, please Email me so we can share the solution with others.