Master Cylinder Conversion - Upgrade

[randyscycle]

I'm with Roy on that one. I stopped using any reman parts for brakes a long time ago for reasons mentioned. Too much to chance when the brakes don't work when you need them most.

I even hate to use any reman steering gears and the like, but sometimes there isn't much choice for some components.

[vacca rabite]

It was a brand new unit. I elected to pay a little more for a new unit.

Hopefully next week sometime the truck will be in my garage and the engine on its way out. Then I will have plenty of space to work with the master cylinder.

This just ed me off. but I am not going to worry about it right now. So long as I can get the truck in my garage, I am going to be able to fix the brakes much easier.

Zach

[chess]

can soft line like stainless steel dot be used from the mc to the hardlines? also what are the thread size of the fittings where the t is. theres a bunch of sizes mentioned but i just want to be sure i already have my stange engineering mc put on.

[Alaska hunter]

thanks for the info and pics

[MJCougler]

Is it new or reman? We quit using remanned m/c entirely due to high failure/poor quality issues.
One day we pressure tested 12 units from 3 suppliers. NONE of them would supply the 900/600 minimum required pressures.
First test on a brand new AC/Delco unit provide the required psi and then some. I think it tested 1100/800.

After reading this thread, I need to bring it back to the top with a few questions. How do you actually test the output pressure to these master cylinders? Is there a "test kit" sold at the auto parts stores that screws into the master cylinder ports to test the output of a master cylinder?

I put a re-manufactured 10-1371 on my M725 last fall, and now I'm seeing that I should have used a 10-1331 which has a 1.125 bore. And, with the 10-1371 with a 1" bore, I do not have aggressive braking that I think I should have. I have HUMMER tires and recentered rims on my truck that I am trying to stop. Am I asking this master cylinder to do too much? Are these two master cylinders inadequate for this larger tire application?

Any advice? Thanks in Advance,

[Barrman]

There are adaptors to plug psi gauges into brake systems. I would suggest you find a loose gravel or dirt road. Going along at idle, slam on the brakes. You should skid to a stop. Don't move the truck. Get out and verify all 4 tires skidded.

If all 4 tires skidded, get a power booster so the brakes get more psi when at speed or start working out doing leg presses.

If just the front or rear skidded. Then you might have a bad part of the master to the other end, air in the line, or about 20 other things.

If 1 or 2 not on the same end skidded. Adjust your shoes and try again until all 4 lock up.

[Warthog]

There is a thread here somewhere where the poster took all the specs for that different M/Cs and found the Corvette m/c worked the best.

[MarkODonnell]

This is a great write-up. Thanks for sharing these details. I'm renovating the brake system in my M715 and following your instructions. If you were to add a vacuum booster, is there a booster that would pair nicely with the 10-1331 master cylinder and fit into the M715 without modification?

Any advice is appreciated.

[Barrman]

Try and find a Jeep Wagoneer or J truck in a junk yard. There is a wedge shaped piece of aluminum that goes between the booster and the firewall. Its purpose was to move the master away from the carb and up a little.

Going with a 1987 Wagoneer replacement booster would be a good choice in my opinion. Several other have done it already. I went Hydroboost because of the diesel engine on mine the last time I redid it all.

[ch47fly]

I”m new to M715 and would like to install a dual master cycler. Nice job with the write up but pictures are worth a hundred words. Can you repost photos I’m not able to view them clear.