I have a 94 V12 that barely stops. I've owned this car for many years and it's always had braking issues. I'm now trying to bring it back to life and this is what I recall.

1) I replaced the pump assembly - No difference
2) I replaced the brake accumulator with a new one, No change

Observation - Not much fluid coming out of the reservoir when changing the pumps, maybe a blockage?

3) Changed the rear left caliper as it was grotty
4) Vacuum bled all four calipers - No change

Any ideas?

Thans

 

alabbasi,

It may help if you can explain the original symptoms a bot better.

Why did you replace the pump and accumulator? What made you think they needed replacing? When you replaced them, did you bleed the low pressure side of the circuit before you bled the wheel circuits?

So, starting with the basics:

- When you turn on the ignition, how long does the pump run for before it cuts out and the brake warning lights extinguish?
- Once the pump has reached pressure and cut out, does the pedal feel firm (but not rock hard)?
- What are the symptoms of the braking? Can you lock the wheels / get the abs to initiate without much effort?

Cheers

Paul

 

Paul, yep the symptoms are always the same.

1. The pump will run for 15 or so seconds and go out but as soon as you hit the brakes it will run again
2. The warning light will also go out and light up when you touch the brake
3. Pedal is low and only one wheel locks. No ABS function
4. When I removed the pump, not much fluid would leak from the inlet hose when disconnected

I suspect that I have either low pressure or a ton of air.

This is all from memory.

 

I would start with a proper bleed of the brakes.

You must bleed the low pressure circuit first, before you go anywhere near the wheel circuits.

Then bleed the wheel circuits using the Teves routine, not the Jaguar routine. If you're not sure how to do that, post back and I'll detail it.

Cheers

Paul

 

I have no idea, but I'll take i'll do a bit of googling before i ask you to detail it.

 

A quick link to the rear bleeding procedure here: https://www.jaguarforums.com/forum/x...3/#post2436982
The low pressure system also has it's own procedure.

 

Thank, I have a handle on bleeding the brakes on the caliper. It's not clear to me how to bleed the master or low pressure circuit. I suspect that this is critical because i'm getting much by way of fluid to the pump

 

alabbasi,

Some years ago, after I had explained how to do this for OrangeBlossom (Alex), he wrote this great post on it. See here:

https://www.jaguarforums.com/forum/x...122634/page19/

After that, make sure you do those rear wheel circuits exactly as explained in my post that was attached by Jagboi64 above. Those rear wheel circuits are not driven by direct pedal pressure. They are powered by the pedal actuation allowing the pumped pressure circuit to drive fluid to the rear brakes. So they need to bled using a pumped fluid routine as described.

Getting rid of air in the Teves system can be a nuisance. But if you do it exactly as the procedure describes, doing the low pressure circuit first then the Teves wheel circuit routine, you should be fine. Let us know how you get on.

Good luck

Paul

 

Paul, thanks. Those were very detailed instructions. From what I read however, it's basically not to let the reservoir run dry and bleed the low pressure circuit by disconnecting the hose to the ABS pump at the elbow. Is this correct?

If so, would it be possible to modify the instructions to do the following:

1) Use a motive pressure bleeder to attach to the reservoir so that I have a container pushing fluid through in a sealed system that does not require me to be in two places at one time
2) Disconnect the hose that feeds the pressure pump at the other side where it meets the steel line. This would avoid me messing with the o-ring at the elbow which I agree , looks very fragile

Thanks

 

Personally I wouldn't try and pressure feed the reservoir. You don't want to pressure that low pressure pipe.

The pipe bore that feeds the pump is small and the fluid is only under gravity pressure. Seriously, you will be fine. Just top up the reservoir first. It will only take a couple of seconds for any air to come out of the pipe and you really shouldn't need to top up the reservoir. If for some strange reason, you did feel that a lot of fluid was coming out and still getting air bubbles, just put your thumb over the end of the open pipe and have a container of fluid handy to reach over and top up. I have never needed to do this. I really don't think it would be necessary.

Cheers

Paul

 

Paul,

Thanks, so is it okay to disconnect at the steel line or must i disconnect at the elbow?

 

So the low pressure brake hose going to the ABS pump is roasted. It seems to be molded around the elbow that goes into the pump. Anyone replaced this hose? Is there a replacement or do you use a regular 5/16 hose?

 

alabaster,

The small rubber hose is not sold separately by Jaguar. I THINK that the small rubber pipes at each end come as part of the steel pipe that links the reservoir to the pump That's still available from Jaguar, part number CCC6365 about $30.

Good luck

Paul

 

Thanks, to confirm, this is this hose comes as part of an assembly with both hoses? I don't see any pictures but the hose marked in yellow is what's perished on my car.

Edit: I just called my local dealer and the parts guy said that that part is not stocked anywhere, and might be heading towards NLA. I can confirm that the hoses are not sold separately. Although we might need to figure that out ourselves.

 

alabbasi,

My presumption (and I may well be wrong!) is that it would come as part of the pipe marked "5" in that diagram. As you're looking at the Jaguar parts diagram, I'm slightly confused why your local Jaguar dealer is saying it's not available? If you go on the Jaguar parts website, it says that part no. CCC6365 IS currently available.

If you can't source it that way, the rubber 90 degree pipe doesn't seem to be anything special. I'm sure you could just source a length of the correct size rubber brake pipe with the correct turn?

Cheers

Paul

 

Correct, except that the elbow seems to be fitted on and either glued or sealed in another way. It will need to be clamped if a replacement hose is used

 

Hi alabbasi

I just typed in the Part Number CCC6365 into a Yahoo Search Engine and loads of Motor Factors have got the Pipe that you are looking for

Just to add to the excellent advice from Paul (ptjs) I would avoid Pressure Bleeding as you could get enough stored up back Pressure to give you what I 'Nicknamed' 'The Teves Fountain Effect'

As after releasing the Pressure and Screwing the Reservoir Cap back on, as soon as you the turn the Ignition on to pressurize the Brake Pump, you could like me get a 2ft Jet of Brake Fluid squirting out of the Hole in The Top Of Reservoir Cap and all over your Car!

Where I fortunately had a Bucket of Soapy Water standing by for any unexpected event that may occur when working on the Brakes, as Brake Fluid will Strip the Paint in an instant, unless you very quickly sluice it down with Soapy Water