Desperate for Mk1 help please

[Neil]

that servo and cylinder is 1985 mk 2 transit

[davev6newman]

My advice would seem simple, thats because it is!

Having had to fit new cylinders on my mk2 tranny i couldnt get any brake pressure afterwards, no matter how many many times i manually bled them.

So i used an Easybleed kit....Bingo! it did the trick. It pressurises the system and forces fluid through better than pumping the brakes. One go with that and it was sorted and the brakes worked fine.

Just make sure you have the pressure in the spare tyre as is stated in the pamphlet.

[Bevluvsrats]

The original Master cylinder is Mk 1, the replacement is Mk 2. Dad's measured all of that before he installed it.

Bev x

[Bevluvsrats]

Dad's also tried the easybleed kit I'm afraid. Thanks though.

Bev x

[Bevluvsrats]

Hi everyone. I have an update, although still not good I'm afraid.

Dad has put the original master cylinder back on. He found a few days ago (can't remember if I posted this or not) that the piston seemed to be getting stuck inside the bore, so he put it on his lathe and cleaned it up before replacing it, and now the piston fits well and flows freely. We still have no pedal though.

Dad gets under the bus to bleed the brakes, and I'm in charge of the pedal. On pumping the pedal slowly, there's no resistance whatsoever, but when I pumped very fast there was resistance for a very short time, like the piston caught on something, then gave way and the pedal would go to the floor again. All during this there's no pressure coming out of the three pipes on the M/C, no pressure at all to the rear brakes and only a slight dripping of fluid from the M/C to the front brakes (this is when Dad takes the pipes off of the master cylinder and watches as I pump the pedal.)

I've just found out that Dad pressure bled on the other Cylinder, the Mk 2 cylinder, so his next step tomorrow will be to use his pressure bleed kit on it.

I've taken some pics of the M/C and also a couple of video clips, including what I said about the strange behaviour of the pedal. Hopefully this link should work and you'll be able to see it all.

http://smg.photobucket.com/albums/v209/ ... gon%20Bus/

Any ideas?

Thank you all again, so very much for wracking your brains as much as you are.

Bev x

[Bevluvsrats]

I forgot to say that the pedal behaviour is exactly what it was doing in the first place, before the shenanigans with the Mk 2 Master Cylinder, so we're back to square one.

Bev x

[whitemice]

I would get a m/c off someone who knows what they are doing as previously suggested.

[El transito]

Hi everyone. I have an update, although still not good I'm afraid.

Dad has put the original master cylinder back on. He found a few days ago (can't remember if I posted this or not) that the piston seemed to be getting stuck inside the bore, so he put it on his lathe and cleaned it up before replacing it, and now the piston fits well and flows freely. We still have no pedal though.

Dad gets under the bus to bleed the brakes, and I'm in charge of the pedal. On pumping the pedal slowly, there's no resistance whatsoever, but when I pumped very fast there was resistance for a very short time, like the piston caught on something, then gave way and the pedal would go to the floor again. All during this there's no pressure coming out of the three pipes on the M/C, no pressure at all to the rear brakes and only a slight dripping of fluid from the M/C to the front brakes (this is when Dad takes the pipes off of the master cylinder and watches as I pump the pedal.)

I've just found out that Dad pressure bled on the other Cylinder, the Mk 2 cylinder, so his next step tomorrow will be to use his pressure bleed kit on it.

I've taken some pics of the M/C and also a couple of video clips, including what I said about the strange behaviour of the pedal. Hopefully this link should work and you'll be able to see it all.

http://smg.photobucket.com/albums/v209/ ... gon%20Bus/

Any ideas?

Thank you all again, so very much for wracking your brains as much as you are.

Bev x

In order to help we really need to see a close up of the piston assembly, strip the cylinder and post some close up photos piston with the seal configuration, and if possible try to get a photo of the cylinder wall.

[Bevluvsrats]

Ok, thanks. Dad's going to pressure bleed it tomorrow, but if he then decides to strip it down, I'll take some detailed shots.

Bev x

[jnwferguson]

hi dont know if this will help but there are 2 different master cylinders for the mk 2 ,1 with 2 pipes coming out for the 2 piston caliper set up ,and the 4 piston caliper set up with I think 3 or 4 pipes you can get a master cylinder from an ldv which is almost identical to the transit one. if your transit has drum brakes I think you need the correct cylinder
good luck jim.

[Bevluvsrats]

Still not good. I need my Transit forum army again guys.

Right, as dictated by Dad, this is the latest.

"After letting the rubber seals soak in brake fluid for at least 5 days, there was some pedal resistance, almost impossible to reach the floor, although still a lot of travel. So I gunson pressure bled fronts first, rears second, all wheels with new fluid. Checked the adjusters were up so the linings were up but not binding severely. I had what I considered a workable brake. I tried it on the drive, it held effectively backwards both with the foot and handbrake and stopped going forwards so I decided to back it down the drive and try it on the road. As is my habit in these occasions I use my left foot on the brake pedal keeping it in a lower gear, and my right foot on the accellerator while pumping the brake. The brakes were even, the front of the bus was dipping, there was just a little too much movemenet to my taste but I felt that once I'd bedded the linings, it would allow for greater adjustment of the shoes, so I continued up hill and down dale with the aforementioned pumpng action, I reached this particuarly long hill, grass verges, no hard kerbs, and I chose to puimp the brakes particularly hard on the downward section of the hill to bed them in. I was even pulling back on the steering wheel to give a little extra pressure to see if I could get the pedal to hit the floor. On about the third press, something went twang, I heard it clearly in the cab, and the pedal went straight to the floor. No braking effect whatsoever. I successfully slowed the vehicle by dipping in and out of the grass verge until I met level ground, luckily not meeeting anyone else. The handbrake held so I was able to get out and check for fluid leakage under the bonnet and under all wheels, nothing was found. I then drove the 8 or 9 miles back with no brakes. The handbrake was only efficient when the vehicle was stationery. On arriving home I changed my underwear (:D) and removed the master cylinder expecting a broken spring, and found nothing. I've checked to make sure the servo unit had not pulled clear of the three bulkhead mounting points, so I wasn't losing pressure that way. The servo is attached adequately to the bulkhead, as is the brake clutch pedal mounting assembly. You will see from the pictures that the master cylinder has 3 pressure outlets. The front two, font and side (nearest the radiator) go to left and right front brakes. The rear pipe goes directly to the T junction on the rear axle via a flexible hose. There are no fittings of any description after the master cylinder in the hydraulic pipes."

There are new photos of the master cylinder in pieces, hope I've got all the angles you guys need. http://smg.photobucket.com/albums/v209/ ... gon%20Bus/

Bev and Roger

[whitemice]

YOU NEED TO GET SOMEONE WHO KNOWS WHAT THEY ARE DOING TO FIX IT BEFORE SOMEONE IS KILLED.

[Bevluvsrats]

That's kind of why I'm here asking for help.

[MrMPuk]

I guess at least you have insurance for when you kill someone.

[Bevluvsrats]

Look, I'm not here for criticism, Dad knows what he's doing, he's a retired mechanic / engineer for goodness sake. And if he knew the brakes were that dangerous he wouldn't have taken it out. They failed after 8 or 9 miles, so as far as he was concerned all was well, and he just needed to bed in the linings. Please can we not lose sight of the fact that I'm here to ask for help?