I finally have brakes!!! Here’s what I did:
Yesterday I received the P30 master cylinder so I installed it after work. I bench bled the master until I got no more bubbles and then after installation I bled the entire brake system completely again. I read the manual for the Mityvac vacuum pump and it suggested putting grease or teflon tape on the bleeders to improve the seal. Grease made a big improvement most of the time. You could just give the tool a few pumps and it would hold the vacuum instead of having to keep pumping and pumping and pumping to maintain a decent vacuum. PLUS, without the extra air I could finally see when I was drawing air out of the sytem and when it was done, rather than just running a crap-ton of fluid through the sytem and hope it got it all. I found out it actually takes less fluid until all the air is out than what I thought. I also found out that the new master cylinder has a much smaller reservoir on the rear brake side than the old master cylinder - I had to be much more careful about running the reservoir dry while running the pump. I did have the grease not work so well on the front bleeders so I put teflon tape on them and that did the trick.
Anyway....I got the master cylinder installed, bled it and then decided to drive to the dirt road to run the abs a bit and make sure I got all the air out. The brakes did feel better, but still not great. Definitely not WOW which is what I was hoping for by swapping on a new and oversized master cylinder. So I cycled the abs probably 6 times and then came home and bled it. I didn’t notice any more air. When all was said and done I had a little better brake pedal feel, but again not great. It was also inconsistent. Sometimes it was like, “oh, there’s the pedal” and other times it was like, “eww, that was mushy”. All the while I never felt like the fronts were really biting - the backs were doing a lot of the work. Big nugget here is that the P30 master cylinder is a direct bolt-on, no other changes needed to install it. Here are some pics of the install:
This is the Raybestos part number:
So tonight was time to install the Hawk pads. I took care to do a good job and not make any mistakes. I burnished the rotors with some Roloc discs to deglaze them. Before:
After:
I didn’t take any pics, but I did grind the outside pad again so the oversized 370 pads would clear the rotor hat. I took apart the caliper pins and to my surprise they were dry! I never took them apart the first time I did the brakes, but assumed they were lubed from the manufacturer. Guess not. Oops. What made me think of that was some other reading I had done trying to figure out my brake problems. Some reading I did made 3M Silicone Paste sound like pretty good stuff so I decided to get some. So I slathered that liberally in the pin grommets to make sure those will slide smoothly. I also applied another coating of anti-seize compound on the metal slide surfaces like I normally do.
So then it was time to test drive and bed the pads. As soon as I hit the pedal once the calipers pumped back up I could already tell the pedal was MUCH harder. NICE! THIS is what I’ve been looking for. So I took the drive and did 5 stops from 70-ish to about 10-15. Much more predictable and it was definitely biting. I was tripping the front and rear abs on dry asphalt! The pads never really felt like they faded much, though I could smell them and I think I saw a little smoke too finally. Very pleased. So then I drove about 10 minutes at 55-ish so they could cool back down. Then I went home and parked it. I’m looking forward to good brakes tomorrow!
So I’m pretty disappointed that pads were giving me so much trouble. Unfortunately there are a few variables here so I don’t know what the smoking gun is. Do those pads suck? Did I screw up the pads because I was struggling with air in the system when I was needing to bed the pads? Were the dry pins affecting the feel? Did the stack up of the red coating on the calipers and the ceramic coating on the pads add some spring in the pedal? All questions without answers right now. I’m just glad it works the way I want now.
Here are pics of the old pads. It’s weird the shims are peeling up....not sure what that means.
