In 2000, they went to the dual piston calipers, so, its a real possibility that newer booster is LESS powerful.... as the brakes are much more effective.

 

Good thought. I ordered the 99 parts. The price even went down overnight while the parts were in my cart, ha.

Will update once installed. Hope this fixes the issue.

Planning on all new lines and hoses in spring.

 

My brother installed the braided stainless flex hoses on his Subaru when he replaced the lines and such. I was actually rather surprised at the difference in pedal feel, from just that one change. Much firmer pedal, and more consistent braking......

 

I did the same thing for my Ram truck and another car I'm driving. The stainless braided brake lines certainly help with pedal firmness and should be the last flexible brake lines I'll ever have to purchase for those vehicles. I purchased the lines from classictube.com for the truck (the front lines) and the rear line from https://crownperformance.com/ when I swapped in the late model Dana 60 disc brake rear. Also, purchased a complete kit of stainless steel hard lines as well for the truck.

 

Holy crap, that's twice the price of the complete set on rockauto. Nah, I'll stick with regular lines and hoses. Whenever I get them. The pedal feel is good, just has more travel at times. I drove again today and it works I just have to pump it twice sometimes.

 

Still have air in there somewhere? Drive it for a few days, and when you get some reasonable weather, try bleeding them again.

 

No, I haven't received the new parts yet. Sorry for the confusion. Just reiterating the current issue and that it hasn't gotten worse as yet.

Hope to receive the new MC and booster later in the week. Will update when repair is finished.

 

Update:
Installed new parts yesterday, including the master cylinder and booster. All went well and easy but the bench bleed took awhile.

The pedal is much firmer now, almost too much. But the brakes feel strong and work much better. Not sure if it fixed the issue with sinking pedal as I only drove around the block a few times. Vacuum seems strong.

Didn't have to bleed the wheels. The bench bleed worked well and the lines went right on without issue. Pretty easy job in all.

Pics for fun. The old booster was nasty. Wow. Not sure what this metal star thing is for. It was in the box with the booster. No instructions with it. The MC had nice bleeding instructions.

 

PROBLEM PERSISTS

The brakes are dragging now. I had an errand to run and had to turn around due to the smell and hot wheels. At certain RPMs the brakes get hard.

I tried using the old check valve and it still did it.

I have tested the new booster and it works great. But when I idle up to 2 or 3k or fluctuate the RPM the pedal gets stiff randomly. I can't determine the specific RPM. It definitely got bad in 4th or 5th gear while driving. Like I suddenly hit a massive head wind. Driving at slow speeds the pedal feels more normal again. It's definitely affected by RPM.

Everything on google I've already tried or eliminated. HELP

 

Removed front calipers and had a look.

The driver side was stuck on. I was able to squeeze the piston back enough to get it off. Wear looks good and even. Everything's pretty rusty but they aren't that old. 2019 or 2020.

The passenger side was not stuck. Seemed fine as well for wear.

All four bushings slid in and out. Plenty of grease. But pistons don't squeeze in all the way. Maybe 1/8 inch left. IIRC that's normal but not sure. Maybe all I need are new calipers.