Read all the threads before posting this one. My problem is slightly different. The ABS pump on my 1989 XJS runs constantly whenever the ignition is switched on. It does not cycle. Depressing and or pumping the brake pedal has no effect on the pump and also there is no braking action. The car sat for six years in my garage prior to my "reactivating" it. Also, during this instance, I removed the ABS pump assembly to gain access to the firewall. In the process (besides disconnecting the two electrical plugs) I had to disconnect the supply and feed lines. Could breaking the integrity of the lines have caused my problem or the six year dormant period (or a combination of both)? Any suggestions on how to proceed???

 

I posted a response in the ABS pump problems thread so here it is

You will need to bleed the ABS accumulator.

Also if you allow the pump to continue to run you will damage it. The manual specifically warns not to let the pump run for more than 2min or the motor will overheat - if this happens the manual states to allow the motor to cool for at least 10min.

I have a full write up on how to bleed the ABS system here

http://warrjon.blogspot.com.au/p/how...teves-abs.html

Hope this helps. Feel free to ask any questions.

 

I can vouch for that. Even with a non-working ABS pump, you will have brakes. You will have to hold the steering wheel with both hands and pretend you are leg-pressing an elephant, and only the front brakes will work, but you will have brakes.

Are you in Texas by any chance? I know someone by that name who lives in Texas.

 

Why would only the front brakes work? That sounds (through experience) dangerous to me.

 

Thanks for the quick response and great info. I suspected I would have to bleed "something." I will try that and let y'all know if it worked. BTW, I am the Bill Johnson in Cocoa Fla, not Texas.

 

Just looked at your write-up on bleeding ABS system. This is the most creative and simplistic method I've seen ever. Kudos to you my friend, you've just saved me a lot of anguish!

 

It has something to do with the way Jaguar designed the brakes. Instead of using something like a vacuum assist (like the rest of the world), Jaguar uses the pressure generated from the pump to BOTH give you power brakes AND operate the ABS. In the event, though, that you loose a pump (can something break on a Jaguar?) You still need to be able to stop. For some reason, they only put the pass-through on the front brakes.

 

Do all 1989 XJS's have ABS?

 

I'm not an expert on XJS evolution through the years. But I do know that 1989 was the first year for ABS brakes. All 1989 exports to the U.S. were equipped as such.

 

Right!

But Jaguar's model year designations for USA cars versus ROW cars can be confusing and often appears irrational.

Cheers
DD

 

1992 V12 XJS.
My ABS pump comes on as soon as you touch the brakes together with the dash warning light. Does the accumulator have to be recharged with nitrogen like the one on a Rolls Royce?

 

Does the warning light take a long time to go out when you start the car?
The spheres do lose pressure over time and as you say need to be replaced or recharged over time; 80 bar seems to ring a bell.

 

Agree. Easier to replace than to try to find someone to recharge. BTW, a new nitrogen sphere for a GM Buick is an exact replacement and is $$$ cheaper than an OEM replacement.

 

I turned on ignition and pressed the brake pedal 6 times although pressure was gone after first press. Pump ran 6 seconds and turned off and light went out.
Both lights come on on first press of brake pedal.
Norman

 

That's the little ball gone bad. If I remember correctly, the GM one is not that expensive and you WILL burn up the pump without it.