P38 brake booster pump replacement

[Alan C]

The brake booster pump on my 99 4.6 HSE is covered in brake fluid, I'm guessing there's a leak somewhere! It doesn't look to be either of the pipe unions, so wondering if there's seals etc that have failed? I know it's non-repairable, so a second hand replacement will probably be required as new one is over £1000

While reading through Rave, the replacement procedure also includes a warning to remove, discard and replace the ABS relay. Why?

CAUTION: Whenever pump/motor
assembly is replaced, the ABS relay must
also be replaced.

18. Fit replacement ABS pump relay.

 

[Alan C]

I replaced the brake booster pump today with a second hand one from ebay. I was trying to avoid having to bleed the brake system as there's only me here at the moment and it's a bit hard to do on your tod! So, I thought I'd try to keep fluid loss to a minimum and once it was changed over I left the hight pressure union loose than ran the pump with cloths about. This seemed to work a treat, lots of gurgling as the new fluid came through then a good squirt of fluid. Shut down then tightened the union and all seems fine, good firm pedal, no warning lights or beeps. However, I didn't change the relay - was this a bad move? Really would like to know LR's reasoning for specifying this is changed???

 

[steve's P38 RR]

Dont look like you needed any help from here lol,

I do though would you know if all the p38 brake boost pump's are the same on all years and all engines ?

 

[Alan C]

There is only one part number STC2783, so the answer to your question is yes.

 

[dogsbody]

I'd imagine that Land Rover's thinking would be along the lines of -

why has the pump failed? It could be a sticking relay causing the pump to run permanently.

the pump has seized - the relay might overheat with the current trying to power the seized pump

Either way with the price of a new pump it would be cheaper to replace the relay rather than risk a second pump.

 

[steve's P38 RR]

There is only one part number STC2783, so the answer to your question is yes.

Cool, Thanks for that.

 

[Alan C]

I'd imagine that Land Rover's thinking would be along the lines of -

why has the pump failed? It could be a sticking relay causing the pump to run permanently.

the pump has seized - the relay might overheat with the current trying to power the seized pump

Either way with the price of a new pump it would be cheaper to replace the relay rather than risk a second pump.

All valid points, yes, I didn't think of it that way. As my pump hadn't electronically failed, the seal between the motor and pump head appears to have failed. It was still working fine, although the accumulator was low and the pump would run on every brake application too. I've elected not to replace the relay as in my case I can't see the point.