Another "refurbish" I am working on......
So again, when I bought the truck the brakes were all good. I did not know I had stripped out mounting holes on the knuckles for the front calipers, that I found when I tore the front end down. Any ways, I went through all that and have fixed it up to just about the max. However, ever since the first time I tore into the brakes last July they have never been what they were when I bought it or what they should be. In Latin America I had it all torn apart and the M/C was dry more than once while I worked on it. I bled it a few times down there but still had the same issue. Here is the issue....
Under very light braking the pedal sometimes goes to the floor. I was sure this was due to air in the lines, since it had not done this since after I cracked it open. I bled it and I bled it some more and then after it was up here in the USA I bled it some more. The problem has not gone away. I was contributing it to a vacuum leak because it seemed like it would do it the most often when I first started the truck and it was cold. Perhaps I thought, before it has built any vacuum, although this just didn't seem like it was or could be the issue. The odd thing to me was that the vacuum actuated 4wd worked excellent and was in and out fast which indicates no vacuum leak. Learning about this vacuum system on the 1PZ/1HZ engine it seemed like there could be a leak with all these vacuum lines so still I pursued a vacuum leak. First I thought perhaps the vacuum reservoir was leaking down from a bad check valve. I replaced the check valve. Next, I wondered could it be the booster? Nah, because a bad booster is a hard pedal not a soft one which is my problem. It could be a bad line, leaking but man I been over all the lines a dozen times with a fine toothed comb! No leaks and I have new lines in varies locations too.
I finally have come to the conclusion it is the master cylinder. What happens is under light braking the brake fluid leaks past the cups. When I brake any harder than light the cups flare out and the fluid doesn't leak past. The cups are getting so old they are needing to be replaced. Even if they were changed once and the M/C rebuilt, 14yrs out of a M/C is good to me, 28yrs even way better! I feel like now I am 99% sure this is the issue. So, I have a new OEM M/C in route to me. Let's see if I am right in the next week or so!
Separate topic. My A/C compressor has worked flawless since I got this truck. Everything about it has been good from the idle up to the switch to the actual cold output temp. However, a few weeks ago I noticed it is leaking down onto the alternator. Obviously the casing is leaking. So I went and ordered up a new OEM re-seal kit for it. I was a little worried since it is still R12. My first call around town on this subject had me not so stoked. They can evac the R12 and re-seal my compressor but they got no more R12. I may not have enough to re-fill even if we capture all the R12 since I have had a leak. I haven't lost much, but still, a consideration and possible issue if I have this shop do it. They can get a keg of R12, I got to pay for it at like $1600! Haha, ya right! They can retro fit this truck to not run on R12, cost is well over $1,000. No thanks!
So, I call around. Bingo, local shop still has some R12. So that is it, evac my R12, re-seal the compressor and fill with new R12. Happy happy! The pulley on my compressor must have started separating some years ago. It was repaired by some tac welds on the pulley to keep it from separating anymore. Works fine actually but is a bit ugly so I decided to finish off this A/C work with an install of a complete new pulley and magnetic switch assembly. I figure, what the hell why not, this has lasted 28yrs and been repaired once.
Ya, the OCD is in full effect for me on this truck. That is just how I do things and it makes me content. For me, that is all that matters, not what anybody else in the world thinks or how they would do it, just how I feel about it. I seem to do alright with my trucks! Plus I believe rebuilding or as I call it sometimes "refurbishing" these trucks was built into the engineering. I am not a strong believer in the whole 20-25yr life Toyota engineered it for and then it is dead. These trucks can always be rebuilt until there is no more parts to rebuild them and the parts needing repair are broken beyond repair. And even then you can retro fit other parts! Guess I came from a world of super rare super hard to get parts for trucks before Cruisers. As such even something like this 1PZ 70-series is a breeze. Try and do a frame off nut & bolt restoration back to 100% original & stock on a 1964 Nissan Patrol soft top! Which by the way only 950 were ever sold here and Nissan changed the trucks every 18-24 months! Now that is a real challenge! These 70-series to me are just plain fun and easy in comparison to something like that.
Cheers