Hey guys,

I just got a brake master cylinder to replace my weeping unit on my 79,and I was wondering what size,and pitch the threads on the lines are that come off the MC? I plan on buying a few short pieces to bend back into the MC reservoir so that I can bench bleed the MC.I have done this in the past on my 83,and still have the lines for doing that,but they are different thread pitch than my 79 which I knew allready. I can't seem to find in my literature what the thread pitch is. Also is this the best practice to bench bleed the MC before installing it? I have always done it in the past,but have had people tell me it is unneccesary.Thoughts,advice?

Thanks in advance guys.

 

a shitty thread pitch thats for sure sorry i cant give you any helpful advice

 

The early Mazdas used a 10x1.25 thread pitch on brake fittings, and this includes the 79-80 RX-7. 81 and later cars use a finer thread, which I believe is 10x1.0.

 

Thanks Stilletoman,I will try to find some lines to bench bleed the master today at the auto parts place.

 

I'll second that. Early cars use 1.25 while '81+ use 1.0.

 

Thanks guys,

To follow up on this I couldn't find any lines to bench bleed this today,but I have not given up yet.I did notice however that the MC has bleeder on the left side.What is this for? Also the guy at one of the parts counters told me there is a thing called a universal bench bleeder,but he didn't have any in stock.Have you guys heard of this,and what are your thoughts on bench bleeding? I have always done it in the past,but if I can't find these lines I may just go for it without bench bleeding it. Thanks again.

 

I dont recommend bench bleeding the master cylinder on old cars with old brake fluid. if you have an air compressor, you can buy the Brake Fluid Bleeder kit from harborfreight. Just attach it to the compressor.

http://www.harborfreight.com/cpi/cta...emnumber=92924

 

Hey Wacky,

Thanks for the reply,but the car has all new fluid in it from about 8 months ago,and I flushed it ntil I got nice clear fluid out of every bleeder. Would you still recommend not bench bleeding in this situation?I welcome input from the people like you on this forum who know what they are talking about,but I don't really want to buy anymore equipment right now as money is sorta tight.Thanks again.

 

I can't find any lines to make a bench bleed system for this MC. One guy at the local NAPA store told me to just keep the rubber plugs in place,and pump it slow by hand,and then install it.He is a mechanic,and that is how he does it all the time he says. The thing is the MC has three threaded outlets,and the proportioning valve on the side look to be mounted on a bracket behind the MC,so I will have to take apart more than just the three lines that enter the MC it seems.Thanks for any help.