I have a 1980 4X4 with stock brakes. It started pulling to the right and in the process of checking this, I found that neither one of the rear brakes were working. So that would make me think the left front caliper must not be working correctly. I find it hard to believe that both rear cylinders and the left front caliper all quit working at the same time. I'm thinking the master cylinder must be bad. If I have to replace it, is there a one inch m/c that will bolt up without any mods? If so, what year model and truck model would that be for?

 

Research dude!! Check FAQs. Prolly needs lots of brake TLC. Flushed lines, maybe even disconnect hardlines to blow out. New wheel cylinder?? Maybe. New soft lines or upgrade to braided SS. List goes on. LC vented rotors, larger yota 4 piston calipers, larger diameter wheel cylinder, dual diaphragm booster....

 

I went through the brake system several years ago before I found YotaTech. It has rebuilt 4 piston calipers with Skyjacker stainless braided lines on front axle. The lspv is blocked open on the rear with new shoes. The m/c was replaced with a stock unit from O'Reilly's. I don't seem to be getting proper pressure at the rear wheels,that's why I suspect the m/c. I know there are people on here that have put the one inch m/c's on so I was hoping to get some help.

 

I have a later model. But if memory serve the one inch bore is direct bolt fit. Dual diaphragm bake booster is another story, think your gen is limited to a turbo 22re one.

I did the rear disc disc conversion this summer with manual proportionate valve and line lock. I love it. Used trail tough's kit. Most of our truck calipers are 4 piston so should have clarified. V6 IFS calipers and land cruiser rotors, beefy.

 

Remove the lspv completely and replace with manual valve. Mine was so gummed up that I am pretty sure it was half the problems with my rear drums not working. Not sure though, ditched the drums for disks on all 4. If you stick with drums you want a V6 truck/4runner master, if you want to go disks out back you should get the landcruiser one, early 90's I believe. Has residual valve front and rear.

 

Well, turns out it was the wheel cylinders after all. Both rear cylinders were frozen up. That makes me think they have been like that since I bought the truck. It never stopped like I thought it should but I put that off on adding bigger tires to it. After replacing the wheel cylinders and brake shoes, it stops like it should now. Lesson learned!!!