Brake issues! Help

[vbgambini]

Wussup guys Im having an issue with my brakes. Ive been searching but cannot seem to find what I am looking for. Sorry if its a little long.

 

I have a 1978 280z. Went to take it out for a little drive around the block just to get it running and making sure everything still works. When I pulled out of the driveway when a few feet and my brakes were almost non existent. The pedal became very hard to push and barely stopping the car even when going 10mph. So I decided after researching that the master cylinder is probably going bad and mostly the brake booster needs to be replaced (Seemed like still original parts)

 

So I ordered a new master cylinder and brake booster from Black Dragon. Disassembled all the old parts. Mostly took out the brake booster, and left the master cylinder for now since it is still full of liquid. 

 

Received my parts from black dragon this weekend. Here are my issues. 

 

Black Dragon part numbers

 

#64-162-Z brake booster

#64-103 Master Cylinder

 

1. The old nuts that went on the old master to booster, 3 of them fit but the top one. The nut cant even be screwed in. It looks like they sent me a bad part. Threads on the stud looked stripped. And even at an angle. But all other 3 nuts screwed in.

 

2. The new master I received has only 2 stud holes when the old master had 4 is that normal? So I said what the hell I will try and make it work. Ill just use the two vertical studs. So I just test fitted the new parts together out of the car, the master cylinder had to be wiggled in since the stud wasnt straight, and now when it slid in, theres a gap between the master and the brake booster. I dont recall there being some sort of spacer on the old master. I even tried the new master with the old booster, slid in perfect but still a gap. 

 

3. New brake booster looks significantly larger than OEM, Measured the rectangular indentation that fits in the firewall on the new one and the old one. The new one is larger. Will it even fit in my car?

 

Just frustrated because I wanted to get this done over the weekend and even ordered SS lines from MSA. And wanted to get it back on the road. Please if anyone can help me. Thanks.

[Dave WM]

Bad master would just sink to the floor, hard to push sounds like booster not working. 1st thing to check would be is it getting vacuum.

[vbgambini]

Yea I know lol. Had you on the other forum. Need more help on the other issues Im having. Anyone chime in?

[sweatybetty]

pictures help alot

[hr369]

which one did black dragon send you? one on left or right?

 

What's the production date of your car? Its on the plate thats located on the drivers side door jamb

[vbgambini]

Looks more like the one on the left. Just not in that black color. Its all gray. Its slightly bigger. Like a couple inches bigger. Seems like a 10'' booster. I also dont have that spacer. And the studs that go into the firewall on the new one i got are still short, not long like the one on the left. Pretty much the firewall studs are the same length as my old one. The one in the picture on the left seem way longer. 

Will mine still work if I can get the old nut to thread through the stud? I believe the production date is 5/78. Black dragon says even having an attempt to put on the car voids a refund or exchange so Im trying to get as much info before I take a shot at it. 

 

UPDATE!!!!

Ok. Had a few minutes to check the car again. I still do have the spacer. It was fused to the old MC but not a problem to break free. Tried to test fit the new booster. Seemed like it'll go right in, just having trouble pushing it through the firewall since the rubber is preventing me from being totally flush. Could I use grease to push it through the firewall hole? Its like a 1/4 of an inch from getting all the way through. 

 

Now if I can only get the old nut to just screw in the top stud for the MC I should be golden. Any ideas? It screws in the other 3 just fine. I dont think its worth sending back and waiting for a new one when it only has to turn a few times. Maybe some washers?

Edited April 18, 2016 by vbgambini

[S30Driver]

Why not just replace the damaged stud with a new one?

Or use an appropriate metric die to clean up the threads on the existing one.

[Mark Maras]

1 hour ago, vbgambini said:

 

 

UPDATE!!!!

 Tried to test fit the new booster. Seemed like it'll go right in, just having trouble pushing it through the firewall since the rubber is preventing me from being totally flush. Could I use grease to push it through the firewall hole? Its like a 1/4 of an inch from getting all the way through. 

 

 

 S30's ("one of the Jims") advice is what I would do. Don't use regular grease on rubber. It will deteriorate the rubber over time. I use Syl-Glide. a silicone base grease. Avail. at most auto parts stores and WM.

[vbgambini]

Good to know. How about a little WD40 to slide it in? Would that hurt the rubber boot?

[Mark Maras]

 I don't have a can to verify but I believe WD-40 has petroleum distillates in it. Not the best but at least you could wipe the WD-40 off the boot after installation. It's the hydrocarbons that deteriorate rubber. If you have any dielectric grease, disc brake grease or hi temp grease in your supplies, use that. They are all silicone grease.

[vbgambini]

Cool. I know I have a high temp lithium grease will that help? I have anti seize and hopefully some brake caliper grease. Those will help?

[Zed Head]

Those are all hydrocarbon based.  Just spit on it, or use soapy water.  It's not a huge deal. And the type of rubber and the application matters also.  The booster seal doesn't move much and the part that does, the accordion shape, probably isn't the part you'll be lubricating.  Plus it's in a protected area, unlike a CV boot (which is packed with grease and exposed to the elements).  Just saying, it's worth consideration, but after doing so, keep it simple.  No offense Mark, if the Silglyde is handy definitely use it (I have a small can of a different brand in the garage myself), but I wouldn't make a special trip to the store for a booster seal.  Just me.

WD-40 is petroleum based also.  That was my suggestion, on one of the two other forums you've posted in.

http://wd40.com/files/pdf/msds-wd482671453.pdf

http://www.devcon.com/prodfiles/pdfs/sku_msds_537.pdf

Edited April 21, 2016 by Zed Head