I'm quite new to this so please bear with me. When bleeding the
rear brakes (just replaced entire rear brake assembly and
reinstalled the cage) I'm getting no flow out of the bleeders with
the ignition on and pedal down. I have been getting some
dribbling, after a while, but no pressure. The ABS pump on the
passenger side continues to run while the key is on and does not
shut off.

To check this problem I made sure that my RES was filled up. I
also checked the low pressure line from the res to the pump and
there is in fact a steady flow of fluid coming out of the line at
the pump. Just in case I hooked up a vacuum line to the pump and
filled the pump full of fluid with a funnel. This still did not
fix the problem. I then disconnected the high pressure line coming
out of the pump from the connection on the firewall. I turned the
key on and pressed pedal down. There is no fluid coming out of
this line. The motor sounds as if it is ''free reving'' with no
resistance and does not shut down.

Would I be correct in assuming I need a new pump? Accumulator? Thanks for any
assistance!

 

You do not need the ignition on to bleed the brakes.

1. tighten up all bleed nipples
2. fill the reservoir
3. turn on the ignition until the ABS pump stops
4. have someone in the car to pump the pedal as you open and close the bleed nipple. Start with the calliper farthest from the reservoir. LHD drive car = RH rear calliper.

 

Hello! Thanks for the reply. Unfortunately the pump does not shut off on its own. Thats why I'm thinking there may be a problem. Previously the motor would run for a few seconds and then shut off when pressure was reached. Now its sounds as if the pump is not pumping anything (bogging sound) and does not shut off at all.

 

There is a special procedure for bleeding ABS brakes. I do not have the info handy but if you do a search you should find it. Also if you let the system go completely dry it is almost near impossible to get the air out.

 

From memory the the procedure is to fill the reservior and turn the igition on until the ABS stops, then bleed.

I completely drained mine and did not have a problem. I will read the procedure again when I get home and post back.

 

Here a couple of pics of the manual saves me typing it out

hope it helps

 

The Jag manual specifies for ABS to do the fronts first then the rears.

 

The manual does list the front first but it also states to bleed the caliper furthest away from the MC. I would start with the rears as per the pre-ABS instructions. There are other anomalies in the manual that are clearly incorrect. It's more of a guide than instructions. LOL

 

Not to open a can of worms or start an argument, but this is the experience I had.
Had my rear brakes R&R'd at a local shop by a mechanic who'd "been doing brakes for 30 years" He could not get the system bled to his or my satisfaction. He said he'd never come across a system like that before.After 6 tries at getting it bled I said screw it and took the car home

With my buddy we followed the book to the letter, farthest from the MC at the front first,(front right on left hand drive car) then the other front, then the rears with the ignition on, furthest first of course. Next I went for a test drive..... @30 mph the car stopped in 2 car lengths.
Just my 2c

 

If the pump seems to go on "forever", it may be that the accumulator (the bulb sitting next to the pump) is a goner. When it goes completely the pump can go on for a minute or two each time you start the car even if the rest of the system is bled. And upon every application of the brakes it will run for 30 secs again.

 

I'm going to try bleeding the brakes again on Thurs. The pump still doesn't shut off automatically and I'm not to hopeful that I'll be able to bleed the brakes with the pump acting like that. From what I understand that should shut off regardless of the brakes being bled properly or not. I also think the accumulator is gone, but I don't want to start throwing expensive parts at the problem unless I know that for sure is the problem. Anyone know of any steps I can take to troubleshoot the functionality of the pump and accumulator?

 

It is getting on for a long time, but try this: Open one bleeding screw, switch on the ignition for about 30 secs. Then close the bleeding screw and proceed according to manual. I seem to recall that under certain circumstances an air lock could form.

I have never taken one of these pumps apart, but I wonder if they are old enough for the seals to start giving up? Anybodu know what type they are, e.g. using rubber seals? Further, do they use rubber seals that are ruined on prolonged dry running?

 

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???

 

Absolutely 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

Jaguar XJS Restoration : How to bleed Jaguar XJS teves ABS

Hope this helps. Feel free to ask any questions.