When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Thank goodness you and Jal turned up, I was running right out of ideas!
But this was the First Time the Fluid has ever gone down in response to pushing the Pedal
I gave the Pedal a Couple of Pumps, which sort of equates to the Brake Fluid going down a half an Inch and then their was that leak you can see in the Photo, so I pulled all the Pipes apart, at which point I could see where I had gone wrong
As although I double flared the Gold Pipe, I didn't flare it anywhere near enough but now I have, so the Gold Pipe with the Inverted Double Flare now Comfortably sits over the Top of the profile on the Green Pipe
So when I've Bled all the Brakes again, then who knows that might work?
Where the reason that it hasn't worked when the Engine was Running, could be due to the Extra Pressure Created by the Brake Booster
The other thing it could be, is that the Master Cylinder may need Bleeding and I for one don't have any idea how to do that, as even if you were to take the Master Cylinder 'off' and fill it with Brake Fluid, while its sort of laying on its side
Then when you try and put it back it looks like all the fluid will run out!
Why on earth did Jaguar not have at least one Bleeding Screw on the Top, as that would have made life so much easier
Hi Jal Thank you for the Video, it could be that as you say, as up to now I have tried everything that I could think of, so if or when I ever manage to Fix it, the result could be interesting, because sooner or later someone else is going to have the same problem, that we will hopefully know how to fix
Way back at the Start of this Thread, I accidentally came up with a way of Closed Circuit Bleeding the Master Cylinder on the Car (see Video) where after a bit more research, I also found that others had been doing it this way for Years
And is still one of the Methods that Shops use Today, as a handy Alternative to Bench Bleeding, that is apparently sometimes but not always necessary, except it seems that I was making one Ginormous Mistake, that could well be the reason why my attempt at doing this was a Total Failure!
Have a look at the Video and see if you can spot what I did wrong, which I only found out from a Video that I happened to find on YouTube this Morning and while I am not saying that this will Fix the never ending problem that I am still having with my Brakes
This will be the only thing that I haven't tried, so who knows it might work, as at the moment I've been getting nowhere!
So retracing my Steps, what I know is that the Reservoir ran dry, while I was changing the Calipers and its also highly likely, that there is Air that is still Trapped inside the Master Cylinder
As it seemed to be working OK before I changed the Calipers, though I'm not ruling out that its possible that I might need a New One, though that is the Nuclear Option! if nothing else works
Where I went Wrong or 'Think' I went wrong, when I tried 'Closed Circuit Bleeding'
Was that I didn't have the Tubes dipping down into the Brake Fluid in the Reservoir
Which meant that when I pushed the Pedal Down, Brake Fluid may have been coming out of the Exit Pipe into the Reservoir but because the Exit Pipe was not dipping down into the Brake Fluid
Then as soon as I released the Pedal, Air was getting Sucked Back in which would not have happened if the Exit Pipe was dipping down into Brake Fluid
That's my Theory anyway and would be interested to know if you agree, as that's what I am hoping to be trying out today
Alex
Going back to a much earlier post of mine on this thread, but in more step by step detail. Your master cy linder bleeding problem is, I believe, the fact that you have no method of preventing the fluid being sucked back into the cylinder from the bleed tube as the piston/pedal retracts under its return spring. Even if your closed circuit technique pipe had been under the fluid reservoir surface (obviously disastrous if not - commiserations, we have all done many silly things on our cars in our time!) there is nothing to prevent the reservoir fluid being sucked back up that bleed pipe, rather than the master cylinder being filled from the reservoir's normal outlet via the M/C inlet port.
In which case you are just shuttling the air bubble in and out of the M/C exit port.
The only easy and reliable way I have found to expel air from a M/C is as follows/
Helper on pedal
exit ports both disconnected (rags under M/C)
helper pushes pedal slowly down and holds it down
you put a finger over each exit port and hold them there
pedal up (forces the fluid to enter the M/C from the reservoir fill port)
pedal down and release fingers as you feel the pressure
repeat from no. 2.
Three or 4 goes will do it. Then connect ports to pipes and bleed calipers normally.
At Last I 'Think' I've Found The Cause of The Problem With My Brakes
And Why The Pedal Goes To The Floor
When The Engine Is Running
Looks like Greg was right all along and that the Master Cylinder needs replacing, as I found out this morning when I Bled the Master Cylinder using the 'Closed Circuit' method that I copied from YouTube before I'd seen Greg's reply
Where while Greg's way may be better, I think the result I was getting was more or less the same, as in the Tube that does the Rear Brakes on the end of the Master Cylinder, after just a few Bubbles at the start of the process, there were No Bubbles at all
Where in total Contrast to the Tube that does the Front Brakes, the Bubbles just kept on coming and wouldn't go away, while the Tube that does the Rear Brakes just stayed Clear
So now I know or 'Think' I know what the problem is, where would be the best place to get a New Master Cylinder, or should I try and repair the one I have got, as this is a job I've never done before
Alex
There are a number of very good companies in the UK who re-sleeve and re-rubber master cylinders. They insert stainless sleeves so never again any bothers. So if no new ones around, this is a great option, better than new. eg
That's the wrong master cylinder.
Orangeblossom, you need JLM12232 for your RHD car. NLA according to Barratt. The LHD one is available, but is over $800. The reservoir is not included, but you're in luck, the RHD reservoir is available for only $400. The seals are available.
I'd suggest finding a rebuilder. They can usually get seals, etc, not available to the DIYer.
But first, take the master loose from the booster and see if the rear seal is leaking or not.
Jon
Although they are very expensive, so I'll either go for a rebuild, although I would be happy with an Aftermarket Part if I could find one
The Crazy thing is I've seen New master Cylinders for around £35 although unfortunately not the one I need although I would be willing to pay around £100-£150 for the right one
Maybe I will dial in that part number and see what comes up
So, as I think we all suspected, there's a problem with the m/c either air or seals. Hence me sounding like a stuck record on the detailed analysis approach to work out where the problem lay.
Jon's provided the correct part number for you (My second stuck record theme, always just go to the Jaguar parts website first to get the right part number.) It's been NLA from Jaguar for some years, although a LHD version is still available new at £611. Probably because of the relatively small number of cars to which it was fitted, none of the big independents seem to sell a RHD OEM or pattern part. However, you might strike lucky with somewhere like autodoc.co.uk. Worth a try.
You'll see from the Jaguar parts website that it's possible to buy the seal for the back of the master cylinder to the servo, but I don't think that's the issue as you only recently mentioned a fluid drop.
I would still try and bleed the m/c properly using bleed nipples to seal off BOTH ports. Then bleed one port at a time using exactly the same principle as a caliper circuit. Open bleed nipple, press pedal slowly, hold, close bleed nipple. release pedal. Wait a few seconds. Repeat whole sequence. And again, and again... until you get a steady flow of fluid out of the bleed nipple on each pedal stroke. Then do the other port.
I did block the Front one off with a Bleed Screw, so I could Test the Rear and there were no Bubbles at all, just Bubble Free Brake Fluid
But I couldn't find anything to Block off the Rear so I could Test the Front
I Think it's 12mm but I don't think I've got one, but I did find a 12mm DIN Male Fitting so maybe I could Solder the Hole up or something like that (that's the hole in the DIN Male Fitting and Not the MC)
How about putting a 2-way fitting on the end of the pipe that comes from that port ( and currently giess to your new pipe joins) and then fitting a bleed nipple to that? Obviously that's linger than just putting a nipple direct on the m/c but should work fine.
I went through every little thing and even did your Test
Both outlets Blocked on the Master Cylinder Rock Hard Pedal
Front Brakes Closed Off Rear Brakes Open (on the Master Cylinder) No Bubbles (But Pedal Went Down)
Then I did the Opposite Front Brakes Open Rear Brakes Closed (on the Master Cylinder) No Bubbles (But Pedal Went Down)
And this is with the Engine Running or Not Running
It seems almost impossible that the Brakes down work and even went round a Bled all the Brakes again
Are you 150% that the Front of the Master Cylinder does the Rear Brakes, that's the only thing I can think of at the moment and not even sure that it would make any difference, so I'm really just clutching at Straws (the 12mm Fitting is the one furthest away from the Brake Booster)
Just wondering if I needed a Master Cylinder, could I use a Land Rover one NRC 8690 as they cost peanuts and look exactly the same (to me)
Auto Doc has ABS 51977 not sure if that is the one you mentioned
First of all, the chamber of the master cylinder that is NEAREST to the servo is the primary circuit and it definitely feeds the front brakes. The chamber FURTHEST from the servo ie nearest the front of the car, is the secondary circuit and feeds the rear brakes.
A couple of thoughts on your steps:
(Every time you do a test with engine off, you should take your foot off the pedal before starting the engine and then waiting for the engine to run before pressing again to test with the servo running.. Is this what you've done?)
1. Both outlets Blocked on the Master Cylinder Rock Hard Pedal
This is with engine off. And then you pressed the pedal AGAIN with the engine on and it was still hard?
I think this is really significant as it implies the m/c seals are functioning ok
2. Front Brakes Closed Off Rear Brakes Open (on the Master Cylinder) No Bubbles (But Pedal Went Down) What do you mean by "Rear Brakes Open"? Did you have the bleed nipple open or a pipe opened before pressing the pedal? Or do you mean that the Rear Brake Pipes were fully connected up to the master cylinder at this point? If the latter, you'd probably need to a full bleed at the wheels first to shift any air that may have been introduced by cracking open the pipe at the m/c.
3. Then I did the Opposite Front Brakes Open Rear Brakes Closed (on the Master Cylinder) No Bubbles (But Pedal Went Down)
Same comment as above
So, my simple mind says that if you have a rock hard pedal with engine running and both m/c ports closed (and presumably almost zero movement before it goes hard), but then you have a soft pedal with EITHER of the front or rear circuits connected and the other port closed, then you have air in both the front AND rear brakes. And all of this assumes that the reservoir level stayed at exactly the same level throughout.
This has been driving me Crazy! but after Tea I felt so Stressed out at constantly thinking about this that I just fell asleep! during which time I came up with an idea that was really out of the Box
So while I'm prepared to get 'egg on my face' I think this might actually work!
Because I suddenly realized why I wasn't getting all the Trapped Air out of the Master Cylinder, where as you know you don't need much to get a Soft Brake Pedal
So Tomorrow I'm going to try it and see what happens, as the Master Cylinder and Brake Booster, were both working fine until I let the Reservoir run dry, so for once I'm feeling quite excited to try it and see if it works
And so no matter which way it goes then I will let you know
Far be it for me to try and dissuade you trying something new!
BUT, if you said that with the engine on and both m/c ports blocked (how dud you do that one at the front? With a bolt?) and you had a rock hard pedal with no movement; then, what little i know about cars tells me you dont have air in the m/c.
When you then connect up the wheel circuit lines and you then get a soft pedal, it means the air must surely be further down the lines?
I reckon that there could be Air Trapped further down the lines and so I'm on a mission to try and get that out, because it seems completely crazy to have those Brake Pipes go up and down like a Roller Coaster in the way they do
Although I am not planning to re-pipe that part of the System, until I have tried my idea (just in case it works)
Note to Greg: only one Firm of Master Cylinder re-sleavers has replied so far and they can't do it or don't do it anymore
Teves Mk111 all is forgiven! at least I know how to Fix that but the Teves Mk 1V is in a league of its own
One of the problems being that the parts are so hard to come by and extremely expensive
So all I can do is keep trying (it's been 3 Months now!)
Having tried almost every Trick in the Book without Success, I decided to go for The 'Nuclear Option and came up with a different way of trying to Bleed the Brakes, which happened to work Amazingly well, as it got every last bit of Air Out
Not only out of the System but also the Brake Lines as well, where as you will see from the Photos, Starting from the Rear Passenger Side on a UK Car, I took a Pipe from the Rear Caliper, straight to the Reservoir, so that it formed a Closed Circuit as I Pumped the Brake Pedal
Then once having done so, I then did exactly the very same thing with all of the other Three Calipers, where I got every single drop of Air out, although unfortunately it didn't solve the problem
For though the Pedal was solid as soon as the process was finished, the moment I Started the Engine, the Pedal went straight to the floor, at which point I have to say I'm right out of ideas
So if you guys have any suggestions for sorting out this problem, then please let me know
From the Caliper to the Reservoir to Close Circuit Bleed them
I also used a Filter to keep out any dirt
Although it got all the Air out, it didn't solve the Problem. so what Now?
08-20-2023, 06:07 PM
