JayJagJay,

Sorry to hear of your problems. You've already been given a lot of good advice by OB on the Low Pressure and the wheel circuit bleeding. Just to add my 2p-worth:

The XJS Teves system is quite unusual compared to most cars. If you really understand it, it really helps in understanding how to set up the brakes and also to diagnose any problems. I'd really suggest that you fully read through the brakes section of the workshop manual. You'll feel so much more knowledgeable and better prepared.

Just to give you my view on how I would now progress.

I suspect you don't have any leaks as I'm sure you'd see the fluid. A pedal going to the floor because of a leak would be forcing a very noticeable amount of fluid out somewhere. A sinking pedal is really only symptomatic of two possible issues; Air somewhere in the system or seal problems in the Actuation Unit. (It's not a Master Cylinder, although it does have one small chamber at the front which acts as a pseudo master cylinder for the front circuits). The Actuation Unit is quite complex and does a number of things to control fluid flow and pump assistance to various circuits, as explained in the Manual.

So, start by ensuring that both chambers in the reservoir are topped up with fluid. There's a front / back division as the reservoir is providing two different parts of the system with fluid.

Now go and bleed the Low Pressure side again. Yes, I know you've done it once but do it again, as you may have had air behind the initial fluid flow because you'd let the reservoir drain. It's really important to have the LP side absolutely right first or you might never get the brakes bled properly.

Once that is done, bleed the rear brakes as per the Teves, not Jaguar procedure. The important point is to pressurise the system via the pump activation, not the pedal, then open the bleed nipple, the slowly press the pedal. This is important as it is the initiation of the movement of the pedal allows the pumped fluid to then be passed to the rear brakes. When clear fluid is flowing, close the bleed nipple whilst the pedal is being held down. Keep checking the reservoir is always topped up, otherwise you'll have to go through the whole LP side again!

When you've done both rears, do the fronts with the ignition off to utilise the fluid flow through the front chamber of the Actuation Unit with no power assistance.

Then see if your pedal is ok. If not, start again! Then a third time, if necessary!

Yes, you can use other methods, but if you do it this way, you'll understand which parts of the system are being used at each stage.

You could (theoretically!) have a problem with the seals in the Actuation Unit but I've never seen a situation where that has been the problem, so let's not consider it yet.

Good luck

Paul

 

HEYYY!

I was just reading this thread, post #21 (see link) preparing myself for the task at hand of bleeding and trying to get brakes right later today (it poured rain here last night)... I came across this portion of a thread explaining that the bleed nipples needed to be on TOP of the calipers? Both? If I reversed them - one would always be on the down side,,, NO?
https://www.jaguarforums.com/forum/x...-118388/page2/

My RH side bleed nipple is on the bottom! Is it upside down OR on the wrong side? Or, what I have no idea..... I'll leave it there.

Comments, suggestions, criticism and laughs,,,, welcome...

 

Hi Jay

It was me who put the Calipers on the wrong way round, which was only spotted by XJSV12 or I would have been there for ever and a day, trying to Bleed the Air out.

The Bleed Nipples need to be at the Top on both Calipers.

It sounds as if you did the same as I did, in which case you will never get the Air out.

 

I get you. I looked at the picture and my RH bleeder is in the exact same place as yours is/was in the photo... Thing is I personally don't understand how "flipping" them would make a difference.

They are kinda mirror images. Or isomers. The one that has the bleeder on the TOP now,,, when moved over,,, will have the bleeder on the bottom and visa versa...

Maybe my visualization or imagination mechanically isnt serving me right now,,, but I don't quite see (from memory) how flipping them will change that.

Please help me out.

 

Hi Jay

It also took me a while to figure that out.

But the Bleed Nipples need to be at the Top, as Air Bubbles Rise and if you've got them on the wrong way round, with one of them upside down.

Then Air gets Trapped in the Bottom which you have put at the Top like a 'Diving Bell'

Confused, me too!

But if you play around with them, it will all fall into place.

 

Yes OB.

I completely get the bleeders at the top, and the floating air bubbles, best bleeding design being that way -

what I am confused about is HOW,,, if I took the one (LH) that has the bleeder on the top now, moved it over to the other (RH) side, turned it around and bolted it down - the bleeder would then be at the the bottom and the one (RH) I take and move it to the other (LH) side,,, that bleeder would then be at the top... I feel like I'm losing my mind, lol

I cannot figure out what I'm missing. Did I possibly connect the brake hose where a bleeder should be, accidentally? I dont think so.

If I have to take these calipers off tonight, I'll be rip ****,,, at myself, lol

 

Hi Jay

Anything is possible! but if they are the Calipers you took off, then they should go back on without any problem.

But I don't mind admitting when I frapped that up, my head was Spinning Faster than a Mechanical

(sorry to use the 'F' Word) FAN!

If you can put up a Couple of Pics, someone on here with a Mensa degree will help you to figure it out.

Unless you picked up a Wrong Set of Calipers from somewhere?

 

they are new calipers, pads, disks, hoses.... i am completely confused. then again, i am not car side. i will have to wait and see til a little later this evening. about 4pm est...

 

Hi Jay

It is remotely possible that they Sold you the Wrong Calipers.

I once bought an Exhaust/Muffler for one of my MGB's (Can't remember which one 'Leo' sorry) and instead of increasing performance.

I couldn't even get the thing to run, so I took it to a Tuning Shop and they changed all the needles in the Carburetters and they couldn't even get it running either!

It turned out that the Exhaust/Muffler was a dummy one that was made for an Exhibition to hang on the wall that had been blocked off on the inside.

So with that in mind its possible for even the best people to screw up sometimes.

This is turning into a Saga!

Can't wait for the next installment. (Lol)

 

Hey OB... Thanks for getting back

I think that you're right... It's the only thing that it could be. They sent me two LH side calipers... I will have to contact them and see what they will do. Its RockAuto who I hear are hard in this kind of situation. Two Reman calipers. Very frustrating.

In the meantime I think I'll contact my local Jag dealer and purchase those two small connecting brake tubes at each caliper. Why not...?

That is, unless I get to the car in a bit and see my royal blunder and can fix this, lol

We shall see

 

Hmmm.

I guess the public forum offers re risk of being the public ***, lol

The didn't send me two left calipers by mistake so much as I ORDERED to left fronts, by mistake.

Don't pay attention and pay the price.

Just ordered the right. Saturday next it is.

 

Hi Jay

We've all been there at some time, it just makes life a bit more interesting.

 

OB One of your mgbs!!!!!!! fulkjnvlks jnvmnlkfgjnbhlnkvjhshjcslk!!!!

 

Hi Leo

I don't get what you're on about!

Is this some sort of Audition to go on 'The Crystal Maze'?

 

an exclamation at my own vehicular inad,inadek inda shortcomings

 

You lost me at-an!