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Brake bleeding

Posted: Wed Feb 21, 2018 9:05 am
by Pedro 70
Hi all,new member so you may have covered this before but I cannot find it.I have a 2.8i 1986. Thought I would upgrade the brakes and bought some new princess calipers. Installed okay until it came to bleeding. Whether using an easybleed or with the wife doing the pedal work, results the same. Start bleeding, loads of bubbles until they stop and only fluid comes though, same on each of the three nipples and nothing, no brake pedal. Will pump up, then nothing. Repeat the process over and over, 1 and ahalf litres worth and same result. No fluid loss anywhere in the system and the master cylinder stays full. Previously with the old calipers the pedal pressure was fine, just passed its mot. i have tried the bleeding the front calipers 1st as per haynes, then the rear 1st, same result. Taken the master cylinder off, no leaks and ejects the remainder of fluid out of the 3 outlets like a rocket.. when pushing the plunger by hand. Any suggestions would be a massive help while I still have some hair and I do not claim on the fire part of my insurance!!!!! I would add that before I realised that the calipers needed two feeds an I only had one supply, the system did pressurise correctly albeit only teo pistons in each caliper working. Sorry to be so long winded but trying to give the full picture. Regards...Peter

Re: Brake bleeding

Posted: Wed Feb 21, 2018 9:30 am
by Peter-S
I put these calipers on my 2.0. They were a real pain in the bum to get good pedal pressure but after one or two tricks and tweaks I got there in the end and the pedal feel and brakes were much better than standard. I then decided to put a set on my 2.8. Couldn't get any pedal pressure even with the experience of doing it previously. Basically I had exactly the same problem you are experiencing. I'm afraid the cure is likely to be a new master cylinder which is what I had to do despite the old one being fine previously.

With regards the feed you can either split the incoming pipe in two via an adapter or use a cross over pipe on the caliper itself. There's a picture of the cross over pipe in this thread
viewtopic.php?f=17&t=38650&start=100

Re: Brake bleeding

Posted: Wed Feb 21, 2018 11:42 am
by Pedro 70
Thank you very much Peter, search is on for a master cylinder now, Capri or Granada. Rebuild kits are available but is it worth going that route given the hassle I having with what I thought was a good m/c. Peter

Re: Brake bleeding

Posted: Wed Feb 21, 2018 12:56 pm
by andyd
Tickover are good https://www.tickover.co.uk/shop/content ... p1640.html

Or Martin (Capri Gear) on here may have one https://www.caprigear.co.uk/

:goodluck:

Re: Brake bleeding

Posted: Wed Feb 21, 2018 1:24 pm
by Pedro 70
Thanks for the info Andy, did'nt realise m/c were so expensive. Dearer than the new calipers themselves ! Peter

Re: Brake bleeding

Posted: Wed Feb 21, 2018 2:04 pm
by Caprigear
I have a master cylinder available.

Re: Brake bleeding

Posted: Wed Feb 21, 2018 4:45 pm
by Andrew 2.8i
Hi Peter,
Welcome to the forum.
Sorry if I'm asking the obvious, but is the car level when you are bleeding the brakes?
If it's not, the bias valve will prevent the brakes bleeding properly.

Andrew.

Re: Brake bleeding

Posted: Wed Feb 21, 2018 5:27 pm
by Pedro 70
Hi Andrew, yes tried that one as well. Car wheel less but dead level on axle stands. Think I’m going to go down the master cylinder change route in desperation. But I cannot understand if air can get into the fluid system why doesn’t the fluid get out of the same route? Thanks for the welcome and comments, much appreciated. Peter

Re: Brake bleeding

Posted: Wed Feb 21, 2018 5:47 pm
by sheff
I bought mine off ebay last year. They seem to have gone up a bit now http://www.ebay.co.uk/itm/TRW-Master-Cy ... Swj85YQYx5

I've got a good secondhand Capri one, if you want to take a risk on something thats 34 years old?

Re: Brake bleeding

Posted: Wed Feb 21, 2018 6:36 pm
by Pedro 70
Hi Sheff, thanks for the info regarding the eBay link. Will probably use that tomorrow. I cannot risk using an older item, thought mine was more than serviceable. Quite fancy the bigger Granada m/c as well. ATB. Peter

Re: Brake bleeding

Posted: Wed Feb 21, 2018 7:06 pm
by sheff
Pedro 70 wrote:Hi Sheff, thanks for the info regarding the eBay link. Will probably use that tomorrow. I cannot risk using an older item, thought mine was more than serviceable. Quite fancy the bigger Granada m/c as well. ATB. Peter
Wise decision!

I think the reason your's has failed, is the fresh fluid and all the exercise you've given the M/C has washed away all the crude around the seals, which has now caused them to fail under pressure. When you apply the pedal the fluid is just leaking past the seals and not pressurizing the brake lines. Its happened to me in the past. Probably safest to change the M/C :)

I had a GPZ1100B2 when I was younger. Scariest bike I have ever riden :burnout:

Re: Brake bleeding

Posted: Wed Feb 21, 2018 10:49 pm
by Pedro 70
Thanks again for your thoughts. They are heavy old bikes, my 900 is bad enough. Peter

Re: Brake bleeding

Posted: Sat Mar 03, 2018 1:31 pm
by Pedro 70
Hi all, just a short update and a further thought. I have purchased a new Master cylinder, not installed yet as far too bloody cold out in the garage. Reading through the Haynes manual though, regarding bleeding the brakes threw up something that Andrew had touched on earlier, the brake bias wotsit. Has anybody had to use the made up tool (shaped screw driver) pushing the ball up in order to bleed their brakes? Will keep you updated re the bleeding. Peter

Re: Brake bleeding

Posted: Sat Mar 03, 2018 2:32 pm
by Andrew 2.8i
Pedro 70 wrote: Has anybody had to use the made up tool (shaped screw driver) pushing the ball up in order to bleed their brakes?
Hi Peter,
I haven't had a problem with it...yet! According to the Haynes manual, the warning light will be illuminated if there is a problem with pressure drop in one of the circuits. If that light is not on, I would suggest bleeding your brakes as normal. If, after bleeding, the warning light is illuminated when it shouldn't be, repeat the bleed process using the instructions in the Haynes manual in reference to the bias valve.

In addition, if you haven't got one already, I would definitely recommend buying an Eezibleed, it makes the job so much easier.

Andew.

Re: Brake bleeding

Posted: Sat Mar 03, 2018 3:49 pm
by Pedro 70
Thanks again Andrew will give it a go next week, weather improving here in Suffolk, temperatue wise anyway. Peter

Re: Brake bleeding

Posted: Wed Mar 21, 2018 4:49 pm
by Pedro 70
Just an update to the thread. New master cylinder fitted, slight difference in as much that the brakes will now bleed to a good pedal pressure, for a minute or so then gradually lose most of it with the pedal travelling further downwards, but not to the floor. Subsequent bleeding ( using an eezibleed) gives in the same result, each time loads of bubbles through all five bleed nipples until the bubbles stop, good initial pedal pressure then more ingress of air I guess. Gingerly taking the car out on the road hoping that something may bed in or click into place (fat chance) did not help. So now I have brand new Princess calipers, brand new master cylinder, less than two year old pipes and braided hoses, no fluid loss. I am at a loss though. So I am now going to revert to my original calipers as that is the last constant I have, when the brakes were last operating correctly. Watch this space ! Classic car ownership is great isn't it, but I'll get there in the end !!!!! Regards Peter

Re: Brake bleeding

Posted: Thu Mar 22, 2018 7:14 am
by pbar
Pedro 70 wrote:So I am now going to revert to my original calipers as that is the last constant I have, when the brakes were last operating correctly.
You have probably solved it right there. The last thing you change, before a problem arises, is very often the cause of it.

Re: Brake bleeding

Posted: Thu Mar 22, 2018 10:39 am
by Caprigear
Have you plumbed in the princess calipers properly? you need to link up some of the fluid outlets. I have only two bleed nipples on each of the calipers that I fitted and I have had no problems at all in getting a pedal.
I would use a vacuum bleeder rather than Eezibleed as the vacuum method pulls the fluid through and the bleeding can be done single handed.

Re: Brake bleeding

Posted: Thu Mar 22, 2018 6:47 pm
by Pedro 70
Thanks guys for your input. Gonna put the old calipers back on this weekend and have a look at the plumbing as suggested. Can I have linked the pipe work the wrong way? A question to all those that have carried out this princess mod, is the set up, braking performance etc, significantly better than the standard 2.8i calipers ? Peter.

Re: Brake bleeding

Posted: Thu Mar 22, 2018 11:18 pm
by Peter-S
Pedro 70 wrote:Thanks guys for your input. Gonna put the old calipers back on this weekend and have a look at the plumbing as suggested. Can I have linked the pipe work the wrong way? A question to all those that have carried out this princess mod, is the set up, braking performance etc, significantly better than the standard 2.8i calipers ? Peter.
This is how the cross over pipe should be. You will then have a single feed in at the top and two bleed nipples.

ImageDSCF4535 by Peter Smith, on Flickr