RangeRovers.net Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
361 Posts
Discussion Starter #1
Gidday all.
Is anybody able to to tell what the operating pressure is of the p38 ABS pump? I assume that the pressure switch controls this by cutting the system when the correct pressure is reached.
I am asking because I have been put on the trail of several alternative models/brands of pump that appear to be almost identical to the RR one except for maybe the accumulator being at a slightly different angle - these would be a life saver for when the pump decides to turn up it´s toes. Depending upon the price of course.

Cheers
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
865 Posts
As far as Im aware the pressure is 80 bar and have tried so with a gauge to test.
Alfa and jag are use abs pumps but pressures differ.

Be worth checking out my blog to see why abs pumps fail
I am in no ways linked to LR though I wish I was cos they must be selling sh it loads of brake fluid reservoirs
 

·
Registered
Joined
·
649 Posts
The pressure, and the test and pass / fail values are in the workshop manual.
As these are free to download I suggest you look there.
 

·
Registered
Joined
·
361 Posts
Discussion Starter #4
The workshop manual mentions 80 bar and a maximum operating pressure of 170 bar for the pump but I am not proceeding any further with the idea.

Yesterday I consulted a local brake specialist workshop and was told that it probably wouldn´t be worth pursuing alternatives. This was because of the different operating pressures for abs pumps but, more importantly, the legal and insurance repercussions. The brakes would be modified with non-factory parts so an engineering report might/would be required ($$$$$) to get it approved for road use as well as my vehicle insurance company having to be notified - more red tape.

A local 4wd service shop suggested that they can service the pump motors on an exchange basis for less (depending upon the problem) than the cost of an aftermarket pump and without the associated problems. This shop also agree with viperover that many problems are caused by not renewing the brake fluid on a regular basis. They suggested that I should just syphon out the old fluid from the reservoir and bleed the system with new fluid. I would much prefer to remove the reservoir, clean the filters etc, and then renew the fluid.
Is it possible to remove the filters for cleaning? - I don´t want to pump all the muck any further through the system.

Cheers
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
865 Posts
Rowant said:
They suggested that I should just syphon out the old fluid from the reservoir and bleed the system with new fluid. I would much prefer to remove the reservoir, clean the filters etc, and then renew the fluid.
Is it possible to remove the filters for cleaning? - I don´t want to pump all the muck any further through the system.

Cheers

Better still remove pipe from abs pump, you may have to cut original non usable clamp, remove filler cap and then remove low pressure pipe to abs pump, note flow, at first it may seem ok but let it all drain out, bet is if its still the original container the very fine mesh screen filters right at the bottom will be blocked.

For the time it takes to clean and let dry I would advise going new on this part as there's also the possibilty that when reverse flow with a water garden is performed damage to the screen filter is highly possible as you cannot remove or see it
check out my blog ((below) and have a dig around
 

·
Registered
Joined
·
361 Posts
Discussion Starter #6
I priced a new reservoir and **** near choked when told the price - about US$300 - NO THANKS!!! I have another car so I can take my time in removing and cleaning the old container. After it is removed I plan to just fill it with water and shake it up to loosen whatever is living inside. Repeat as above until clean (as possible) - I won´t use pressurised water to blast the internals just in case I ruin something. Then it won´t matter if I leave it to dry for a week just to make sure.
As a matter of interest should I clean the inside with just water or would you suggest some sort of degreaser or maybe dishwashing liquid - to help loosed the filter muck.

The place that quoted me the above price told me not to remove it - ´you will have grief!. They said just bleed the system as it sits and use the new fluid to push out all the old fluid. They didn´t seem to understand that doing that would not clean the filter and so would leave all the muck inside or, worse still, try to push the muck through the system. Not what I want as it seems to defeat the whole purpose of cleaning and leaves the ABS pump open to just the sort of problems that you mention in your blog.

This is a job that I can take my time with at my leisure.
Thanks
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
865 Posts
Dont you have a aftermarket place that sells LR parts, if they deal with Britpart then they should be able to oder the part in for you or buy from the net.

The reservoir is a WABCO part

Replacement is easy, bit of a bitch but advise against having a beer when doing it
 

·
Registered
Joined
·
701 Posts
Hey viperover. I've got an idea for the reservoir. I want to feel right about taking my range on the road, the screen got ripped in the reservoir and now I need to spend the ridiculous amount of money to replace a simple plastic box 8~ . I started thinking about a way around it and thought maybe to put a fuel filter on the out going reservoir line. The only thing I would be concerned about would be the filter not doing a good enough job... I'm still going to replace the reservoir, but don't want to splash the cash for one now and figured it would be good for a temporary fix. I am skeptical as to whether or not its viable, but let me know your thoughts.
 

·
Registered
Joined
·
361 Posts
Discussion Starter #9
I actually had the same idea today - installing some sort of fuel filter in the ´out´ line. It would be a very easy thing to do provided it wasn´t too fine - I wouldn´t want it to restrict fluid flow too much. Then again a standard P38 fuel filter would suffice because it must flow a reasonable amount of fuel.

By the way the price I mentioned previously WAS from an aftermarker dealer - but it was still a factory part. I have not been able to locate any aftermarket manufacturers.

Another thought that I had (still under investigation) might be to cut out the bottom of the standard item (where the filter is), clean it and then get it plastic welded back into place. Probably a bit hair-brained but I refuse to pay the price that is being asked. Which retard designed it that way anyhow and how can LR justify charging that price for a plastic box?!?
 

·
Registered
Joined
·
701 Posts
I had one priced at $179 from rover parts.com, not as bad as $300, but still. Funny thing, the RR classic reservoir is only $79. I have a filter, its metal though and I'm just worried the brake fluid will corrode it. I suppose its worth a shot though... I'm tired of cringing every time I hear the pump kick on and praying that some crap doesn't get stuck in the relief valve.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
865 Posts
Yeah this thiught did cross my mind sometime ago when I discovered this reservoir problem.
I did do abit of research regarding the type of filter to use but came up empty handed but Im not defeated

A normal fuel filter will not work and will break up even if its steel/ally, the filter material needs to be plastic or very fine steel mesh and the only filter that I have seen come close is for motor bikes, even these are rare..

Its given me a idea as there are special filtration companies about and will investigate further but Its not going to be easy to try and break through the screen filter within the reservoir, though I will see if a screw driver can be inserted through the supply pipe to ABS pump and see if it can be broken up that way

I retail reservoirs here genuine for R980 ($130)but new stock has gone up and will be retailing them for R1190 ($158)

I recently replaced my reservoir and the high pressure hose from ABS pump to modulator, done so I know its not going to pop due to age and then burn out my original ABS pump since 96 with 250 000k's (154329 miles)

Im still advise new is the only way to go, cleaning does work if done carefully but the risk is to the owner as brake modulators are not cheap
 

·
Registered
Joined
·
361 Posts
Discussion Starter #12
Well I have now done my brakes. I removed the reservoir - and made a mess with the fluid that leaked out. Quick grab the hose and flush it away to save the paint. I rinsed it out several times with plain cold water and it took forever to empty each time (lots of chambers). I then reverse flushed into the outlet pipe using a garden hose - the outlet appears to be about 1/2¨ so I clamped on my 12mm garden hose and ´presto´ - a clean filter. Well as clean as possible. At his point I used a piece of wire to check the state of the filter and could not detect any movement - thank goodness. I then boiled the kettle and filled it with boiling hot water and gave it a good rinse - the boiling water evaporates quickly and aides drying. Then I just left it in the sun for a couple of days to dry thoroughly.

Today I reinstalled everything and did a complete brake bleed as per the manual instructions - I reckon that 3 hours for a solo effort isn´t too bad. It is just a tedious and time consuming job but at least I know that it is done.

As a matter of interest regarding installing an in-line filter I consulted a company (I spoke to one of their engineers) who sell pretty much all fluids - hydraulic, compressor, engine and trans oil etc and was surprised by what I was told. A micron is .001mm (1 millionth of a metre) and an average car oil filter is rated at about 30microns. Modern diesels with common rail etc need about 5 micron (maybe less) to keep the fuel extra clean and so they suggest that any in-line filter rated at 30 microns would be more than adequate for what we are talking about. A reckon that any motorcycle shop will have what we need - all plastic construction.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
865 Posts
^^^ but a new reservoir is nicer, you can see the level alot easier too

I can confirm that bike filters are made of fine mesh plastic But no spec on them is available

So take your chances vs a brake modulator, me I would go new
 

·
Registered
Joined
·
361 Posts
Discussion Starter #14
Something I have noticed today and I have only noticed it since I have been working on the brakes. It is quite possible that the problem existed before but I never noticed it - I would just get in and drive and vehicle noise hid the the possible problem.
Since I bled my brakes yesterday I have noticed that the ABS pump runs for about 40-45 seconds on start up - when left overnight. AND it comes on, for about a second, every time I press the brake pedal after that. If I press the brakes 6-7 times in quick succession I get the ABS,TC and BRAKE lights all coming - they don´t blink but just go out again when the pump has pumped up pressure again.
Initially I thought that I had botched up the bleeding operation but, after thinking it over (and becoming paranoid), I thought that it might be the accumulator ´going south´ - symptoms of long initial pump and then regular small pumps. I recall reading that I should get about 5 pedal pumps before the pump comes on again.

I am going nuts trying to figure it out and, to be brutally honest, I am also beginning to understand why people bad-mouth RR´s.

I have read many different posts here trying to figure out what is wrong but I am just confused now so any advice will be considered. The temperature is over 30 again today (and no wind) so I don´t really want to go outside.
 

·
Registered
Joined
·
167 Posts
I believe that those would be the signs of a failing accumulator.
 

·
Registered
Joined
·
361 Posts
Discussion Starter #16
Thanks Terry
Oh well - just another thing to add to my shopping list. I think that I will put the tyres and disc rotors off a little longer as this is somewhat more important. I suspect that our local prices will be sky-high so I might just have to import one myself.

Cheers
 

·
Registered
Joined
·
701 Posts
Terry is right, my accumulator did the same things before it started to fail.
 

·
Registered
Joined
·
701 Posts
Bought mine from Miami Rovers for $200 brand new. Not sure if they ship internationally...
 

·
Registered
Joined
·
361 Posts
Discussion Starter #20
I wrote to Miami Motors, regarding if they ship internationally, but have not yet had a reply. No matter as I have been flat out with work and house upgrades. I am not using the old girl at present to thats ok and she can sit a little while longer.

As a matter of interest the workshop manual indicates that the abs pump switches off when it reaches 170 bars of pressure - is anybody able to confirm this figure as correct? I am working on a hair-brained scheme so please just humour me regarding the pump pressure switch-off.

Cheers
 
1 - 20 of 20 Posts
Top