AndyBee

Hi guys!

My brakepedal went to the floor the other day, but just on som occations, which led me to the MC. Since i planned to use the car to my wedding, i stupidly thought that this was an easy fix... NOT!

The MC is of a very perculiar type, the piston is shared with the vacuum booster. I took it a part and the inside was just a rusty piece of junk... the cylinder was corroded, so i must get it resleeved.

BUT where do i find the spare parts, the quirky looking slotted pieces that i donīt even know the right vokabulary for and the rubber parts?

Must i send it to e.g Apple hydraulics, or does anybody know where i can find parts or even a used master cylinder?

Since i live in Sweden itīs very expensive to send the old MC forth and back for a complete rebuild.
Please help me, the summer is short in this country!

BTW, we used a friend of mine and his -65 Bonneville to the church, very nice ride!

Tedd Thompson

Have You Tried USA parts? They list a bendix part #s4.901g and a Delco part # s4.9o1h These are rebuilts that require a core charge but if shipping is more the the core just buy it out right. There number is 800 872 2013 or www,usapartssupply.com. Good people to do bussiness with, some what spendy though. ....Tedd

hialeah56

At fusick.com they got the rebuid kit for both types (delco-moraine, and bendix) as well as a rebuild service
btw the link is in my signature

AndyBee

Hi guys! On both Fusick & USAparts i only found a complete booster and MC together.
I donīt think itīs nessesary to rebuild the booster since itīs OK.

But i got started thinking about the corroded cylinder, maybe itīs possible that the piston donīt move in the corroded part of the cylinder? since i changed the brake shoes, maybe the piston disturbed old dirt which got the rubber to leak.

Iīm going to take it to a brake specialist to see if he think itīs possible to use it without resleeving. I ordered a rebuild kit today, unfortunately it donīt come with the special sun feather looking washer. Does anybody know what happens if this washer (called "finger type expander" in the service manual) that is mounted on the secondary cup have some broken "fingers", will the cylinder leak internally?
Complicated stuff, i think

rocketdownunder

Hi andybee , i'm going through the same thing now but it was my booster that went , I orded the complete rebuild kit from fusicks , while pulling everything apart my mechanic found some corosion in the master so they are doing a complete rebuild of both , when it comes to brakes and the fact you have the booster/master out of the car ,do yourself a favour and get the whole lot rebuilt for peace of mind, we have some great workshops here in aussie town , i bought the kit from fusicks and gave it to my mechanic,should be getting the car back any day now , when i get all the details i will let you know what was done, just to clarify my mechanic isn't doing the rebuild a brake specialist is doing it, here is the link http://www.burtbrosautomotive.com.au..._services.html
cheers chris

rocketdownunder

Andybee got the 55 back today, WOW! brakes are awsome , not sure of exactly what was done but they used the rebuild kit i bought from fusicks and they honed and resleeved the master, rebuilt the booster, the pedal feels great, I'm sure you can find a specialist there if you supply the rebuild kit , but like i said you may aswell build both master/ booster while its out.
cheers chris.

AndyBee

Sure, the best thing would be to rebuild both the MC and the booster. BUT, the summer is really short in this country, i prefer to rebuild the booster later during the winter.

It suddenly occured to me that this type of MC is the other way around from a common MC. There is not a piston with a cup that slides inside the cylinder, instead the cup is fixed and the piston moves in it

This means that when i checked the corroded part of the cylinder, i believe now that this part never contacts the rubber cup, hence no leakage between the cylinder and the cup, this area looked fine.

Itīs more important that the piston is smooth an that the inside diameter of the rubber cups is undamaged and that they donīt leak.

But i still have the problem with the finger type expander washer, since some fingers are broken, it may lead to inproper sealing of the rubber cup against the piston. I havenīt a clue where i can find this type of washer, itīs not included in the rebuild kit that i bought.

On the other hand, maybe the expander washer only is there to lock the rubber cup, so it doesnīt move when the piston glides through it, if so, it doesnīt matter if a few fingers are missing?

Does anyone have any idea how this work and where i can buy this washer?

AndyBee

Finally got the MC fixed, if it can help anybody i can tell you that the finger type expander probably is not necessary, since the replacement rubber cup is thicker than the original and therefore donīt need any expander to hold it in place. Although corroded, the MC was not corroded where the cups are mounted. So this was not a problem.

When i mounted the whole thing together and tested the brakes, the pedal was quite hard. I dismantled the booster in its place under the floor to see if there ***** any leaks. But i didnīt find anything wrong. I took out the piston and monted it back again, and it worked perfectly!? I guess the piston where stuck in some way. Now my only problem is dragging brakes, but i will start a new thread about this.

Thanks everybody fore helping me!!