Hi everyone,

First off thanks for all the data and advice on a bunch of topic, i'm new owner of a Jaguar XJS convertible US spec 1989 and i did have a caliper stuck. So ive redone all the caliper front and rear.

Before doing so no brake light no lock light on. The main symptom was the car pulling and bad smell of brake bad and overheating of the rim. I didnt drive that much.

I ve carefully drive back to my shop.

Since that i took calipers out , rebuilt them, i got apparently no air in the system following the procedure for bleeding the brakes.

I since find out i need to purge low pressure side. i wonder if there is any specific procedure. if it should be done with ignition turn on or not? pedal hold down or not? or just undoing the hose clamp or both side?
i did read the topic about the teves bleeding procedure but i think i missed first step.

Try to reach few people around here (France) for help but didn't help that much. I'm sure few people have been through that issue so hopefully can get the trick.

thank you for help much appreciated

 

Hi gtv2c

Bleeding the Low Pressure Side of the System is quite simple really, although you need to be Careful that you don't get any Brake Fluid on the Paintwork or it will Strip it in an instant, so first job is to cover everything up with Towels and stuff rag all around the Brake Pump

Also have a Bucket of Soapy water handy to wash down any spills and you could also spray some WD40 around the immediate Area for extra protection as it could make a bit of a mess

Put the Keys in your pocket and Don't attempt to switch the Engine on or touch the Brake Pedal

Assuming you have the Teves Mk1V Master Cylinder Actuator which you should have on a Marelli 1989

Take a good look at the Brake Pump and especially the Braided Pipe that goes onto the Brake Pump on the end of which you will see a Plastic Elbow going into the Brake Pump, which is held in place with a little Spring Clip

First job take the Spring Clip out and don't lose it! because you have to pull and jiggle that Plastic Elbow out of the Brake Pump which has a Rubber 'O' ring on the end of it, which at this stage you won't be able to see (because the elbow with the 'O' ring on is pushed tightly into the Brake Pump)

Although before you do anything else get some Tin Foil and make up a Tin Foil Channel to guide any Brake Fluid as it runs out to underneath the Car into a Container for disposal and stuff old rags all around the Brake Pump and anywhere else that Brake Fluid might flow

And whatever you do don't let the Reservoir run out of Brake Fluid or you will have to Bleed the Brakes all over again, which even with Halloween coming up, is not the kind of a Nightmare, that you would want to buy into

Ok so now we get to the Fun Part, as basically what you have to do is pull and jiggle that Plastic Elbow out of the Brake Pump and since its been in there for 30 Years it won't want to come out that easy, although you might get lucky and it does

Whatever you do Don't Break That Plastic Elbow, or you will be Crying Big Time for a Long Time! so take you time and be Careful, with a Capital 'C'

Next: As soon as you pull that Plastic Elbow out of the Brake Pump, Brake Fluid will pour out, although it won't be under pressure as this is the Low Pressure Side, so you can put your finger over the end to stop the flow if you need to and even catch the Brake Fluid in a Jar (which is a good idea to do anyway)

Where the Basic Principle is, you carefully pull out the Plastic Elbow and then let Brake Fluid Pour out while at the same time making sure the Reservoir doesn't run out of Brake Fluid (for which an Assistant comes in very handy)

Then when the Brake Fluid (Flowing out of that Plastic Elbow) goes clear and purged of any Air Bubbles, you then put the Plastic Elbow back into the Brake Pump and Clip it in place with the Pin (in other words you do the whole thing with Brake Fluid running out on 'The Fly')

After that pull any Rags that are covered in Brake Fluid out from underneath the Car as you don't want Brake Fluid dripping all over the Fender/Wing or anywhere for that matter and then Wash down any Spills but don't go mad as Water and V12 Electrics do not Mix 'Ask me how I know or rather don't!'

Here is the Full detailed procedure complete with loads of Photo's to show you what to do and if you are very lucky the whole procedure will be drama free, with hardly any Brake Fluid spilling out anywhere that you don't want it but its a good idea to take precautions just in case

How to Bleed the Low Pressure Side of the Teves Mk1V Master Cylinder Actuator

 

thank you for that very detailed advice. i couldn't find your thread ! I'm glad i did!

I did remove the pin and the plastic elbow and get fluid out . Doing so with a pressurisation system tighten on reservoir, is that an issue? it did sputtered a little bit. When flow was continue i let it go for 20 more second. and then i put it back in with still brake fluid going out.

 

Hi gtv2c

The idea is to get Brake Fluid running out freely without any Air Bubbles, so personally I would not have tried to pressurise the Reservoir as that could be Counter Productive, as you only want Brake Fluid flowing out under gravity and not jetting out in a way that you cannot Control

Different Story when your Bleeding the Brakes though, you could use pressure bleeding for that but I prefer to stick with the method described by Paul (ptjs)

 

i just redid everything bleed by gravity the low pressure hose. then bleed twice each caliper rear and front. PEdal is hard but i still have lights coming on and off. Ive seen somewhere that the abs could memorize error and i should drive it 20mph to erase them. Ive not seen anything like that here. Do you know anything about this? thanks a lot?

How many liter i should get thru by the rear caliper to make sure all fluid went thru? i did two run of 15 second pump?

thanks so much. It's beautiful to not be alone in this mess !

 

ok so good news i got brake and system seem to be bled as i got no air in the system. I still got the brake light on and lock as soon as i press brake pedal. Also the pump is starting at each stroke.
From what i understood on the TEVES system the pump should be heard running when you put ignition on and then only every other brake action but not every single stroke. Am i right?

is it a possibility that the accumulator black ball is faulty? is it a known issue? how can i test it?

Anyone has used this one ( sorry if the link is commercial but its not advertising, its for the reference)

https://www.ebay.de/itm/BOSCH-Drucks...IAAOSwoCNfaj9d


thank you for your help

 

Hi.
I fitted one of these a couple of months ago. All works fine. My pump would run every pedal push now with the new accumulator fitted it runs on start up an then every 6-7 brake applications.

 

do you mind to tell us why you decided to change it? i mean what was/were symptoms that you have to decide to change it. And if it totally fixed it or not? thank you so much .

I'm not sure i need to replace it or not

 

I changed it because the pump was coming on with every pedal push which isn’t right. The accumulator stores brake pressure and should be enough for 5-7 brake applications. Leaving as is the abs light would come on and it would have ended up burning the pump out. I also had a problem with a sinking brake pedal high was cured with new fluid an a good bleed. The old fluid in my system was hideous. I have also fitted a remote bleed nipple kit to the rear brakes so future bleeding and fluid changing is now an easy job. This is the old fluid.

 

oh my god the color of your fluid is scarry !!

So the symptom are same as mine, the pump is running at each brake action and light ( brake and lock) go on. When i hit brake gently it tends to not happen. You think it's the ball the issue? as i said earlier i flush this system for hours even days! i got cristal clear liquid at every caliper.

is it a good test to turn ignition off then hit the pedal a dozen of times to build pressure then turn ignition on and count the second the pump turns? if its a few (lets say under 10-15s ) it's probably dead ball? can you confirm or anyone?
thanks for advice

 

With a good accumulator when you first turn the ignition on the pump should run for 15-30 seconds to pressurise the accumulator ball. The pump will then run to top up the accumulator after 5-7 brake applications. Your accumulator ball sounds very suspect and if it were my car I would definitely change it. Be very careful if you do decide to change it as it will be tight and also it’s very important to make sure there is no stored pressure in the ball. Normally this is released by pumping the pedal 20-30 times with the ignition off so the pump doesn’t run. Mine changed easy with no problems but others (Orangeblossom) have had brake fluid spray everywhere.
Rob.

 

Oh by the way my hideous fluid was from the previous owner not changing it. I will now be changing it every couple of years.
Rob.

 

As Robbie has said, you need to verify if possible that the accumulator is charging, rather than the pressure relief valve having failed and not allowing charge-up.

Turn off ignition. Press pedal 20+ times to release pressure fully. Turn on ignition, how long does pump run before cutting out?

Whilst ignition still on, Press brake pedal repeatedly with pauses in-between. How many presses before cuts in?

Paul

 

thank you for responding, so i did the test twice to make sure . Both times it was about 15s. And i did another test, once pressurized i press the pedal to check if pressure is maintained and every pedal hit i can clearly hear pump starting and stopping as soon as i get off the pedal !

What's the diagnostic doc?

Black ball sphere to change? Would you go with one from SNG ( not branded)for 300€ or the ebay one branded BOSCH for 100€ ?

thanks for your response guys

 

Well I have fitted the Bosch with absolutely no problems. I got one through a local motor factor who we deal with through work and paid £73.00 inc vat.
Rob.

 

i did take brake pad off to check how the piston react to pressure on pedal with ignition off and on, and i dont see them moving .. may be a millimeter but they had plenty of room to get more out. isn't it weird?

same on each side on the front

 

Are doing this by yourself? If so I can’t see how you could actually see the caliper pistons moving while pushing the brake pedal. Also pushing the brake pedal with no pads fitted is a bit risky as you could eject the pistons from the caliper. If it was me I would put a piece of ply in place of the pads then stamp on the pedal you will know if the pistons are working as they will leave a nice impression on the ply.
Rob.

 

yes we are two of us and i did put a piece of plywood between disc and pistons. they should move frankly right?

 

so i did re-check pistons are moving when pumping on pedal and get to the plywood and get back in as they should. But they don't necessarly operate very simultaneously at the beginning, once its pumped up to the plywood they do. I did bleed an extra couple time each caliper and i didnt get any air. i think i gonna change the sphere


any thoughts? advice? support? :-))

 

The pistons might be a bit sticky if the car is not used regularly mine certainly were. I just kept working them back and forth and they freed up fine. If it was me I would change the accumulator out. If you do as noted above please be careful.
Rob.