Problem with brake system of dodge t110

[gordon]

It seems very unusual to me to oil that cylinder with the engine oil, but if that is what the manual says ...

The return spring will be to pull the PEDAL back, not the master cylinder pushrod.

If the return spring is in place, pulling the pedal back, then it comes down to two possibilities;

1. You are not getting full vacuum on the side of the piston when you release the pedal - though you say you have already checked this.

2. The cylinder piston is sticking in the bore.

I would suggest you clean and oil it again, then run it again and see if it sticks again. As long as it is easy to clean I'd do that a few times before I thought of trying anything else.

[serge]

Hello GORDON

Of course there is a pull back piston spring inside the booster. Normaly with it action added to vacuum at the front of the piston of the booster, the brake pedal should return at it idle position after been released.
As showed in my previous pic (and as I saw on an other DODGE T110) there is no pull back pedal spring.

I think that my problem is due to the rubber of the piston. Please,can you give me the name of the specific oil you told in your previous post

Regards Serge

[gordon]

I'd guess you know as much about these cylinders now as anyone you will find on here.

I think the name of the oil is vacuum cylinder oil, or booster cylinder oil, though when I had to service my DUKW hydrovac I used light jack oil (for a hydraulic jack) It has to be quite light and not attack the rubber seals, which a lot of ordinary oils will.

This sort of stuff...

http://cgi.ebay.com/Hydraulic-Jack-O...3286.m20.l1116