Okay, quickly searching through the forums it seems as though the anti-lock light is fairly common on the xj40's so i'm after some checks i can do to narrow down what i need to fix/replace.

-Car was purchased with an anti-lock code on the dash.
-Brake is pretty spongy. I have to put quite a bit of pressure on to stop quickly.
-Previous owner reckons it just needed a brake bleed but i'm starting to think the issues are actually related. I will be carrying out a bleed regardless though as the fluid is quite dark. What DOT rating do they take?
-Brake booster and master cylinder are visually ok.

 

Hi Jay,

Welcome to the Jaguar Forums!

My first instinct would be to suspect that your accumulator sphere is no longer holding pressure. Run the engine for a few minutes to pressurize the brake boost system. Shut off the engine, then press and release the brake pedal repeatedly, counting the number of times before the brake pedal goes hard. Report back to us with the number of pedal depressions and we'll try to help.

Other known issues include the hydraulic pump, the pressure/warning switch, the ABS over-voltage relay, the ABS ECU and others, but the first thing I would do is the above pedal test to see if the accumulator is storing adequate pressure.

It would also be worth bleeding the brakes, furthest wheel from the master cylinder first, then working your way to the closest wheel to the MC. Once you get the system functioning properly again, I would recommend a full flush to replace all the old fluid in the system with fresh new fluid (which, I'm assuming is the green-colored Hydraulic System Mineral Oil (HSMO) in the case of your '88).

Cheers,

Don

 

Cheers! Ill have a look tomorrow and get back to you.

I'll pay a visit to the local jag dealer to get some fluid then!

 

You might call your dealer before making the drive in case they have to order in the HSMO. I recall hearing that it was getting difficult to find, so your dealer may not keep it in stock.

 

ahh thanks for the heads up i work just across the road from my dealer so i might go check at lunch

 

Okay, update time (finally).

Started it today and took her for a little spin. Brake pedal goes about half way before really kicking in. and on full brake it feels too slow to stop.
I noticed a vacuum sounding noise when in reverse especially with the pedal partially in.
Turned the car off, pumped up the pedal. Went hard after 3 goes but there's about an inch play in the pedal (putting this down to bad fluid/possible air in the system?)
Hope this sheds some more light on the issue, aiming to get some fluid this week and give it a bleed before im away for next week

 

You'll need to rule out air in the system to do a proper test of the accumulator, but I won't be surprised if your accumulator is not storing sufficient pressure and needs to be replaced. Please keep us informed.

Cheers,

Don

 

I'll try do it sooner than later then. How much am i looking at for the accumulator? and where's a good place to get them? i imagine dealers will charge top dollar

cheers!

 

Yes, the dealer price will be astonishing. You'll have to shop around. You can get the Jaguar part number at jaguarclassicparts.com. For the '90 and later cars with the Teves brakes there is a GM/ACDelco part that works, but as far as I know, no one has found a similar option for the '88-'89 cars.

Check with the good independent Jag parts specialists like forum sponsors Coventry West, SNG Barratt and Jagbits, who offer discounts to JF members. You can also check with Welsh Enterprises, Terry's Jags, Motorcars Ltd., Rock Auto, Parts Geek, eBay and Amazon.

Cheers,

Don