[ParkerLander]

New p38 owner trying to figure out all the bugs. 2002 with bad ( or no) maintenance.
When you hit the brakes the traction, brake and abs lights come on momentarily with this sound.
From what I read it seems it's the abs pump or the Accumulator .
Any insight would be appreciated!

***here is the
VID https://www.youtube.com/watch?v=vcE3EI2pCr4

 

[Bolt]

Most likely cause is a bad accumulator. Pump should run every 3rd to 5th push of the brakes depending upon state of the brake pads, air, etc.

Good news is it is the easiest fix on a P-38!
Get a new one, unscrew the old one, and screw on the new one.

 

[Markoz]

Depressurise the brakes first tho! It will save you getting a nasty surprise!

 

[Bolt]

Dang! You spoiled the surprise!
Sorry, ya gotta pump the brakes with the ignition off about 30 times to be sure it has fully depressurized prior to step one.:roll:

 

[Gilbertd]

But if the accumulator is completely knackered (which it looks like it is), he'll probably only need to pump them a couple of times.....

 

[ParkerLander]

Thanks All, Yea I found the thread of how to test the Accumulator but ( as others in similar threads have mentioned) it does kind of go round and round leaving you to believe it could be the pump , seals or check valve. I did the Grommet rebuild in my 99 Disco but then decided the Master was toast and just replaced the Unit as well as did the shuttle valve re-wiring and fix which in the Disco caused ( what was referred to as the 3 amigos ) similar headaches. This Accumulator Ball is an oddity to say the least!

 

[Bolt]

But if the accumulator is completely knackered (which it looks like it is), he'll probably only need to pump them a couple of times.....

The key word there is the second one: "If".
If it is knackered, I agree, a couple will deplete it. If for some reason, it is not the problem (Unlikely) Then for safety's sake, pumping it a bunch of times is good policy.

 

[ParkerLander]

Got it , Thanks! I'm all about not getting an Accumulator off the head

 

[Gilbertd]

It's too heavy to leap up and bite you, it's the jet of brake fluid that comes out that causes the amusement (for everyone except the person standing there covered in brake fluid). The system is completely different to a Disco, it's fully powered. The pump generates pressure and the accumulator stores a quantity of fluid under pressure. The brake pedal is pressure sensitive rather than movement sensitive, which is why it doesn't move much, and all it does is open a valve to let the stored fluid under pressure through to operate the brakes.

 

[ParkerLander]

Well got the Wabco Accumulator off ebay and installed and it was definitely toast. Now upon breaking the lights are gone and I have a nice firm pedal. 'The ABS light comes on and stays on until I roll it down the road a few hundred feet and then goes out. I do hear the pump come on so guessing maybe the brakes were not bled correctly, just a thought guessing that the former P>O replaced the ABS unit not having a clue about the accumulator. Will start with that and go from there.....
and not sure at this point how it's all tied together ( still just learning the RR) but the EAS system has been compromised to say the least.

 

[Bolt]

ABS waits until you have gone a small distance to be sure it is getting good sensor data.
Pump will run every 2nd or 3rd push. With good pedal and assume good brakes as well as ABS, I do not necessarily think it needs bleeding?
Was it as easy to change as advertised?:razz:

 

[tarphenry]

Hi it is normal that the Abs stays on until you reach 5mph to enable the electrics to check that the sensors are working.

 

[Gilbertd]

Air in the system will give a delay in the brakes coming on rather than a long pedal as on a conventional system. You press the pedal, fluid rushes off to do it's thing but an air bubble in the system has to be compressed before the pistons in the callipers start to do anything, hence the delay. If it's only a little air, you may not even notice it, but you'll notice the difference after you bleed it out.

 

[Bolt]

Thanks Gilbert, good point. It is an unusual system and takes some getting used to, but seems quite forgiving for all of that.

..........So, His accumulator was "Toast" Would that then be classed as "Soggy" Toast???:dance:

 

[ParkerLander]

hahahh yea it was soggy toast......had a " twangggggggggggg" sound to it. 5 Min. change in and out. Just took an oil filter wrench to it and it loosened right up.... small thread count so just a few turns to remove. Well it seems that issue is solved so I'll move on. Thanks for all your Inputs and info!~
Now if only the sunroof was this easy