Brake Pedal Vary Hard to Push Down and Brakes feel like there's no Booster on my BJ8

[Patrick67BJ8]

Since it's free to enter this contest, I'm going to take a SWAG: The large vacuum/air piston is stuck. The canister has a thin dry lubricant coating and if (when) it wears through ... well, you get the picture.

That's where I'm going next Bob. If it's dry as a bone is there a recommended lubricant?

 

[RAC68]

Hi Patrick,

A while back I used Sandstrom 28A andis called Solid Film Lubricant and is an air-dry formulation that comes in aspray can. A friend didn't want to wait to order this lubricant and went to the local parts store and purchased a spray can of a PTFE based spray dry lube. Since my rebuild was so many years ago and my booster is still operating, I would go for the Sandstrom again, however maybe others can comment on the other.

Ray(64BJ8P1)

 

[Bob_Spidell]

I used the Sandstrom too, and have not had any issues, but it's mighty expensive. When I bought it, it cost a lot to ship because it's considered hazmat, so I ordered two cans, but both went bad after a couple years. It has an expiration date, and they mean it.

I too found some Dow PTFE ('teflon') dry lube on Amazon, and I haven't bought/used it but would consider it.

 

[Jim 58 BN6]

I've used the Dow stuff at work, and for our purposes, it worked well. The surfaces that it's applied to need to be very clean, though.

 

[Patrick67BJ8]

It looks like a rebuild is needed. There's some fluid in the air chamber. I've tried adding a photo but can't get it to work. Nothings working this week!

 

[Patrick67BJ8]

It looks like a rebuild is needed. There's some fluid in the air chamber. I've tried adding a photo but can't get it to work. Nothings working this week!

Booster Troubleshooting Check List. This is on their site. Check Valve was second item to replace. Boost is on its way to San Jose.
https://www.pwrbrake.com/Themes/powerbrake/Content/pdf/bulletins/Technical_Bulletin_12VB.pdf

 

[RAC68]

Hi Patrick,

Boy, you learn something every day. I didn't even remember having a check valve on my MK2A so didn't even consider the issue. I am wondering that since your MK2B check valve is on the bottom of the booster chamber, could the fluid that you found In the chamber have caused the check valve to malfunction and would work properly after the fluid leak was fixed. I know that you have sent the booster away to be rebuilt so knowing this would be for the next booster diagnosis.

Just thinking,
Ray(64BJ8P1)

 

[Patrick67BJ8]

Hi Patrick,

Boy, you learn something every day. I didn't even remember having a check valve on my MK2A so didn't even consider the issue. I am wondering that since your MK2B check valve is on the bottom of the booster chamber, could the fluid that you found In the chamber have caused the check valve to malfunction and would work properly after the fluid leak was fixed. I know that you have sent the booster away to be rebuilt so knowing this would be for the next booster diagnosis.

Just thinking,
Ray(64BJ8P1)

Hi Ray, the Check Valve is located at the hose connection of the Servo. I would say it's on a side location but I don't think any brake fluid caused a malfunction of it and actually dont think it was bad, but I did drill completely through it so it's now just a fitting. I talked with Power Brake today and was told that they don't have the original Check Valves but what I did to the old one was okay and as long as I had a Check Valve in the line, which I do. I told him about no air release from the Servo after driving, shutting off the engine, and pressing down on the brake pedal. He said there shouldn't be, or something like that. Looking on the inside of the Servo there was some whitish color grease in it. I do remember back in the '70's a guy who rebuilt his Servo had a sticking problem and he felt that the rubber grease that came in the rebuild kit wasn't enough to adequately coat the Booster Chamber so he bought a large tube of the Girling grease and massaged the Booster chamber with it and problem cured.