brake master cylinder

three counties · Post by **three counties** » Tue Jun 23, 15 7:09 pm

hi all,driving back from biling on sunday and the brake pedal went down to the floor,checked the master cylinder for fluid and the rear chamber was empty,this works the front brakes,topped it up and got home.it had been leaking fluid at the rear of it,have taken the master cylinder off today and have got a new one to fit as soon as i can,i now have to bench bleed it and have made up 2 brake pipes and fittings,i have done this before on modern cars but the instructions say that you only push in the piston by 1 inch,in case you damage the seals on the piston.does this sound right ?any help with this please

Pete · Post by **Pete** » Tue Jun 23, 15 7:23 pm

Yep, don't go OTT but make sure that both chambers bleed correctly and then you are good to go. There is also a bleed sequence and be careful that the shuttle in the proportioning valve does not move over and block one port off.

In many respects it is better to just open all the brake caliper / cylinder bleed screws and let gravity to most of the work.

PS - was it you with a Caravan on the back following a Buick that was also towing near the A14 on Sunday?

three counties · Post by **three counties** » Tue Jun 23, 15 7:35 pm

yes pete,that was me and my brother,went up there there late thursday unill sunday,had a good weekend,got a trophy on the saturday for the 3rd winner,car looked better when it was raining

when i bleed the brakes i try and let them work on gravity,have got a easy bleed kit but it wont fit on this ,would you bleed the front ones first?or does it matter.probaly push the piston in by a inch and see how i get on

Pete · Post by **Pete** » Tue Jun 23, 15 7:41 pm

Personally I prefer more than 1" Thrust!

I think it is Drivers Front First, Pass Front second, Drivers Rear Third, and finally Pass Rear, but the least pressure you can use the better.

I had an old Skylark with Drum brakes and I used the Caravan to stop the car - scary stuff before the Disc conversion...............

three counties · Post by **three counties** » Tue Jun 23, 15 8:01 pm

yes your right,it did get worried,the back brakes were working ,i think.did think about calling the aa out ,but i took my time driving home,have got a front disc conversion to go on,but i am doing a prom night this week,so i need to get it back on the road as soon as,thanks again

Rebel · Post by **Rebel** » Tue Jun 23, 15 11:55 pm

Not wanting to confuse matters regarding bleeding of brakes etc, but I've always followed the rule of furthest wheel away first, so if the master cylinder is on the left side of the engine bay ( as you look at it from the front of the car ).
The first wheel to bleed would be passenger side rear, then drivers side rear, then passenger front and finally drivers side front.
Always managed to get a good pedal with this method.

autofetish · Post by **autofetish** » Wed Jun 24, 15 7:15 am

As said open all the nipples up a tiny bit and leave it a night

three counties · Post by **three counties** » Fri Jun 26, 15 2:39 pm

have now done the brakes,i did what rebel said,regarding the bleeding them,all good.as usual things didnt go to plan.checked my paper work and i renewed all the braking system about 9 years ago,apart from the master cylinder.so i thought it would be a good idea to replace the 4 wheel cylinders,the front ones worked a treat,but the rear ones just kept leaking ,where the brake pipe goes in to the back of it,did buy a set of brake fittings as well,these didnt help,made some new pipe up with the old fittings,still leaked.turns out that they wasnt made correctly,made in china.ended up fitting the old rear cylinders,untill i get another new set.so i can use the car for a prom tonight,glad i checked them again before i went out for a test drive,thanks again,mick

Pete · Post by **Pete** » Fri Jun 26, 15 3:55 pm

Glad you are up and running and did not let the Prom date down...

Rebel · Post by **Rebel** » Sat Jun 27, 15 12:47 am

Good to hear you got it sorted, hope you have better luck with replacement cylinders.
Try rockauto.com, they advertise in the traders section on here and have a discount code