Master Cylinder
 

i am trying to rebuild my 69 master cylinder. I got the snap ring off but having trouble getting the parts out. I got them pushed up and down with a screw driver but it will not pop out. I have it soaking in deep creep and pushed them down and got some emery cloth in there to clean it up a little and it still will not pop out. Anyone have any suggestions to get the parts out of there. Also are there replacements for the bleeder. They did not come in the rebuild kit I got from Ames. I looked in the catalog but I only seen them for the front calibers and the and the rear cylinder. Thanks, Marc.

To get the internals out I have ... closed the bleeders, plugged front line outlet with my finger and used a rubber tipped compressed air blow gun on the fluid port in the bottom of the front reservoir to blow the parts out ... be gentle of course ... and make sure the back is wrapped in some towels or something so you don't blow the parts across the shop.

Thanks for the tip. So far I have tried this twice, one with the air pressure at 120 and today 150. So far no luck. I sprayed brake cleaner in the fluid ports, then will spay deep creep in there and try it again. Thanks, Marc.

I have seen MC with a retainer screw that goes down from the reservoir into the cylinder bore that retains internals ... don't think I've ever seen one on a GM, but they do exist on other types of MC ... see any screw heads in the bottom of the reservoir?

Yeah, around 150 psi gets pretty scary, obviously not the solution.

Yes, there is a 5/16 bolt in the front reservoir. I am trying to attach some pictures of the two master cylinders that I have. The one with the bolt in it was going to be the one I was rebuilding.

I am no MC expert by any means ... but have you tried removing that bolt and see if the internals will come out?

Last resort if you are replacing all the internals anyway would be maybe drilling a hole in the back and using a slide hammer to pull it out?

Yes, the stop screw is creating interference and must be removed before removing the piston.

I am going to remove it next, but I didn’t want to bother if it was not a GM one like you mentioned it may not be. I saw the post from will slow GTO and shows the bolt stoping it from coming out. I tried drilling a hole in the back too, that didn’t work for me either. Thanks for the suggestions and help. My fault for not looking at the service manual. I am so used to asking all you knowledgeable people, I forget to look at what I have. Thanks, Marc.

Yes that the bolt. Thanks for posting that. I should have looked in the book. It’s the little things. LOL, thanks, Marc.

It looks like you have an original, ‘pot belly’ style master. I had mine sleeved with stainless steel tubing by these guys. 5 years and 7000 troublefree miles so far.

http://www.karpspb.com/

I took that 5/16 bolt out, hooked up the air pressure and it still did not come out. I finally drilled a hole in the back of the plunger on an angle, put a screw driver in the drilled hole and got it out finally. What a pain. Time for some sandblasting a little honing some paint and hopefully back in the car.