My worst nightmare......... turn on the key after the car has sat for a month and as usual I listen for the brake pump to stop. It did not!
I have no hand brake calipers and the cable is cable tied up so i could drive it.

turn key on to position 1 - pump runs continuously so i turned it off, waited and run the car... ABS light stays on as does the hand brake light even though I pulled it up and down. Hand brake cable needs pulling to fix that and i assume / know it has nothing to do with my pump issue.

So back to the ABS - pump running continuously problem, light is on as are the warning lights. I do not think it is a wiring problem, but never say never ... there has many a wiring updates when it was converted from left to right hand drive. Obvious with new insulation tape and wires etc. Accumulation ball looks new.

Drove the car a meter forward and back, its on ramps and that did nothing. I have been careful not to let the pump run to long... Brake peddle is hard (flush the brake system not long ago) but lacks the booster feel (I think on my short drive LOL) Really wanted to drive the car to the biggest British show on Sunday but it does not look likely.. wife says sell the thing to expensive to maintain... that my friends is not an option!

So.... after reading some posts there are many directions on where to start..... first up relay? what next and which relay is it?
I will now look in the manual to see but wanted to post this for the great wisdom and help this forum provides....

so thanks for any help!

 

Hi Duke

I think you'll have to make a start by bleeding the Brakes again, only just make sure you do it in the way that (ptjs) Paul describes and don't forget to also bleed the Low Pressure Side of the System, or you will be getting nowhere anytime soon

And just to Cheer you up even more, I was recently watching a Video which seemed to tell us something that some of us already know, that when you drive an XJS you should be prepared for some pain!

Unless of course you don't want to drive one of the finest Sports Cars that Jaguar ever made

Bleeding The Low Pressure Side Of The Teves ABS

Don't be Tempted to unscrew the Black Ball Accumulator, as there is the kind of pressure in there that you'd find in an Oxygen Bottle where if it didn't fly off and kill you or knock a hole through your Bonnet/Hood and then of course assuming you survive, then you could be looking at a full respray of your Car

After it's been covered in a Mist of Brake Fluid 'Ask me how I know or rather don't'
obviously it can be done but you need to know what you're doing and be aware of all the risks involved and know the way to depressurise that Ball before you start

Not a job for a 'Newbie' as its one of those jobs I'd rather leave to a 'Shop'

 

OB thanks for the reply - the brake flush was months ago and everything has been mint.
When i did the flush i only bleed from the calipers and keep filling the reservoir.

Had another look... pump run non stop... if I pump the brakes they have gone spongy a bit and firm up after many pumps.
The yellow light comes on and off as I pump. Key in position 1



.here is whats on the dash with ignition on after 30 plus seconds... pump running... the blown bulb light comes on when pumping the pedal...????

 

Dukejag,

As you know, the pump runs to pressurise the accumulator until sufficient pressure is achieved.

So theoretically, a pump running continuously would seem to be because it can't achieve sufficient pressure, or it doesn't know that it's achieved the required pressure.

That implies that you'd look to ensure you've got fluid going to the pump. Maybe just bleed the low pressure side to verify. After that the problem would seem to be with either:

- the electric circuits that control the messages telling the pump when to run - Check all the wiring and plugs
- the pump. - that's difficult to test
- the PRV. - it's possible but a bit messy to check. I'm not sure if you can do that without removing it.
- the accumulator. - That's difficult to check unless it's fully charged.

I'd start with low pressure side bleeding and checking all the wiring connections and see if that resolves it.

Good luck

Paul

 

There is a pressure switch on the side of the pump assembly... Unless there was a big Ol puddle of brake fluid under the car, I might start poking around there. I wonder if the switch alone can be had? Maybe take it off after the pressure has fallen in the system and clean it up with brake cleaner? I'd also poke around the relay to see if it's failed on... Could be. Considering how much they cost and how hard to get I would be happy that the doggone thing was still pumping... Pls don't let it cook!

 

Greg... you will be proud.... looking at the pump running problem. open a box of beer, read the manual and 32 checks, lost 10min of my life and waking up - never see those minutes again.....OMG please do not make me go though those checks.
1 beer - stereo turned down, pump runs on.. swap relays... there was two the same .. pump ran on.

2 beers - Wiggle wires around relays and the pump runs on...

3 beers - yep - remember the pump down time..15min -I even got a temp reading...20d c... cool to touch, was well warm last night .OMG
Beat pressure switch with plastic screw driver 10 x unplug pressure switch and replug ..took an effort...

4 beers - pump ran and stopped- nearly got a woody! OK lets try again... how many pumps... after being married 20+ years the pump counting has reduced some.!
20 plus pumps- no brake pressure... wait.... turn on key..... pump runs 52sec.. stops

5 beers (Doing a Kiwi effort here, the Aussie effort would have ended before now..... their heritage is, founded by crims and cheaters... only have to look at their cricket team ...lol (just a wind up for Greg)
LOL will that get me cancelled!!!!

6 beer - waiting another 15min - just in case again - - pump brake 25 times to de-pressurise the system.
Turn on key to position 1 and 50 sec and the pump stopped. .. yea is an under statement.... read above.

7 beers - Neil Young playing hard - its been an hour + now since last key turn, - lets turn on that key.. zero pump run, this is good, pump brake and the pump ran after 3 pushes and ran for 6sec.
Pumped the brakes heaps and max run was 11 sec - so the ball thing needs replacing..would be my guess??? comments ???

7 beers - Got 17yrold to sit in the car and pull and push the hand brake to make the lights go out.. nope. Pull only like he can only do, and forgetting to explain EVERY detail ... push the button on the handbrake.
All the while I am laying under the car pulling on the hand brake cable... the 100 times he pulled it up and down, me yanking, that FNK cable under the car and that light did not go out.
DID YOU PUSH THE BUTTON on the lever??? and bingo the cable stretched out and the light went out. No spring pressure needed, cabled tie it up ....yea ... another fix

8 beers - Boy starts the car ... up to temp, all lights out... OMG - I am driving this thing to the show.
8 beer - been about an hour plus since car started... turn key to 1 - how long... to charge the brake system 6 sec.
That will do me... next report will be me making it home and pictures of the BRIT show in NZ.

 

cheers!
Dont drink and drive!

 

Dukejag,

Love the update! Sounds like a damn good excuse to drink some beer and make progress on the car! Well done!

Based on what you said, I would suggest that the accumulator could be fine and you just had a lazy pressure switch which you've now resolved. Even if it goes back to taking 50 seconds from fully discharged to get to pressure, i wouldn't condemn the accumulator. I've seen plenty of XJSs that take that long. And the fact you've now got down to much quicker seems to indicate that you're in good shape!

Cheers

Paul

 

I just looked around for prices on these things.
Scary scary scary...
Like, criminally expensive

 

Hi Duke

Well done!

You may have just discovered a 'New Fix'!

Was it as really as simple as unplugging and then re-plugging the Pressure Switch electrical plug, plus a few gentle Taps with a FBH!

Glad you're able to make it to the Show and hope you also get back without any problems!!

 

Thanks - I went and test the pump this morning.... 6sec and up to pressure.
Got to be pleased.

And it raining hard, not good for tomorrows show!
Jay- Not something I was looking forward to buying...are they available new?
PT - it seem that beer always tastes best when the Jag gods and looking down on you fondly!
OB - For me the tap tap tap - unplug plug unplug plug is my go to now... until not!

Just thinking out loud here but it seems these things may not like sitting. Turning on the key once a week may now be my go!

 

Hi Duke

Well done for the Second time to day!

And I am going to try that fix, as my other Car 'Cherry Blossom' has developed a similar fault as I have not used her while rebuilding the Cage on '50 Shades' but you could be missing one Vital piece of equipment!

These Pics cost Peanuts on ebay but for removing the Clips on Injectors and now ABS Pressure Switches! they are worth their weight in Gold!



'into each life some rain must fall' though not during your Car Show!

Good Luck (OB)

Alex

 

OB - glad you mentioned those picks...I have some.. I just wiggled the plug off, I looked at the wire on the plug but could not work out how to pull the wire to make plug removal easier... so where / how do you use these things on these plus.
Oh and I was gentle... side to side action and off it came.

And to add .... turned key to position 1 - and the pump did not run... after sitting for hours, then 25 pumps on the peddle to de pressurise the system and it took 40sec to stop. So it went from 52 to 40.... I will do this again tomorrow and update if the time drops. Sounds like PT is right - thanks

They always say a Jag needs to move or die, a bit like us old folk!

How often do you test the ABS so the valves work?
I am thinking I need to do this more often..

 

Dukejag,

I dont think it's necessary to "exercise" the abs valves to keep them working. I've not heard of a valve block failing through lack of those valves switching.

The 2 killers of the valve block are occasionally the deterioration of the ribbon circuits, but more usually, sediment build up from infrequent fluid changes. Then, when the valve opens and shuts, a tiny bit of sediment gets under the seat, jamming it and causing the car to dive violently to one side. And braking harder makes it worse!

So, frequent fluid flushing is your saviour!

Paul

 

Hi Duke

I never bother Testing the ABS as on '50 Shades' I just use the Car as normal and the Brake Pump always works and cuts out as it should, though it probably won't do that anymore now that I've said that Lol

The Picks are just for removing the Clips on the Injectors if they won't jiggle off and same with anything else that has those Clips

But a question I forgot to ask was when you did the Plugging and Unplugging of the Pressure Switch, did you have the Ignition Switched (ON) all the time?