[perucho]

Hi everyone! First post here but lifetime Land Rover fan. I've had 3 classics, 2 DIs and currently a 97 p38. Aside from the common leaks it's been a great vehicle but recently the bakes have been acting funny. After a brake service, the RR came back with a very spongy brake pedal. Sometimes you had to press it almost all the way down to get it to stop. So I sent it back and the mechanic said that everything appeared to be normal and that, just in case, he bled the brakes again. Well, that din't really fix it. Since then, and because I replaced the air suspension with coil springs (no more air pump running), I can hear the brake pump running often. It runs everytime I press the brake pedal. And the pedal still feels spongy. One thing that helps is to take the brake fluid reservoir cap off and re-tighten it. When I take the cap off it's obvious that the reservoir is pressurized and I don't think it is supposed to be this way. When the cap is tight and allows the reservoir to hold pressure, the brake pedal feels normal (firm). Any ideas? Do you think replacing the accumulator would fix this? Do I need to replace the whole brake booster? Any help would be greatly appreciated. Thanks!

oscar

 

[Rewmer]

Sounds like the accumulator is failing/failed. its the ball shaped thing ontop of the pump.

 

[perucho]

Would that make the brake fluid reservoir to be pressurized? It doesn't hold a lot of pressure but it does make the brake pedal feel firm when the cap is tight.

 

[SERSAN]

Hi,

I have the exact same problem... Do I change the acummulator? I don´t believe that this problem only happen to us :think:

Cheers

 

[TehPriest]

To be accurate it would more probably be the non return valve in the ABS pump. Bt as they are connected it makes sense to replace the both.

ray:

 

[perucho]

Thanks for the reply. Is the pump serviceable? I would hate to have to replace it just because of a check valve.

 

[perucho]

Two more questions: Could it be the brake modulator? Where can I buy an ABS pump check valve?

 

[TerryY]

Pressurized or has a vacuum on it?

viewtopic.php?f=3&t=37012

Cap should be vented too if it is like every other car I have owned. Otherwise it could have vacuum holding the fluid from normal flow.

 

[perucho]

Pressurized or has a vacuum on it?

viewtopic.php?f=3&t=37012

Cap should be vented too if it is like every other car I have owned. Otherwise it could have vacuum holding the fluid from normal flow.

Good question. It may be vacuum. And yes, the cap is vented but getting it very tight limits how much it's vented and helps (or at least I thought it did) the brake pedal feel. But now you have me thinking that maybe it's a vacuum problem and it gets better when I open the cap and not necessarily when I tighten the cap. I'll see how the pedal feels with no cap (with the RR parked) and how often the pump runs. I'll also clean the mesh just in case. Thanks!

 

[perucho]

Okay, I started the RR (has been sitting for about a week) without touching the reservoir cap. It took about 40 seconds for the pump to stop running. Touched the pedal and the pump started running again. Then I took the cap off. The pedal felt firm and the pump run for 1 or 2 seconds every other time I pressed the pedal. So it must have been vacuum like TerryY mentioned. I turned the RR off and pumped the pedal about 10 times. Started it up again with the cap off and it took about 15 seconds for the pump to stop running. I'm going to clean the reservoir this weekend and hopefully that takes care of the spongy pedal. How often is the pump supposed to run?

On a slightly different note, there is a click half way down the brake pedal travel. You can feel it more that you can hear it. I've been reading the long thread about the modulator's plastic piece that has the potential to fail and leave the truck without any brakes. I'm going to replace it just in case.

Thanks for the help!