88RX7Rag

I'm having a problem with my 88 verts brakes. The car will stop, but the pedal will keep moving to the floor if i stay on the brakes. If i release the brake and step on it again i get a stiff pedal, but again it works its way slowly to the floor.

Using the search on here it sounds like this is a master cylinder problem, or possibly a seal on one of the calipers though i'm not lossing any fluid in the master cylinder that i can see. I can't find any evidence of brake fluid at any of the 4 wheels as well.

My question is this:

My brake pads are due for a change (all of them). Could this problem simply be that my pads are just worn down or is this more then likely the master cylinder or something else?

I'd like to kill 2 birds with one stone if possible. Though i don't want to replace the master cylinder if nothing is wrong with it at the same time i'd hate to replace all the pads only to find out i still have the pedal to the floor problem.

Thanks for any advice.

Digi7ech

iTrader: (1)

not pads. Sounds like a leak in pressure some where.

Check for leaks and then maybe it's the master cylinder.

lacycw

See if this might be your problem.

https://www.rx7club.com/showthread.p...14#post2940814

- Cooper Lacy

NZConvertible

You are correct. What is happening is under pressure the fluid is moving past the seals within the master cylinder, causing the piston to keep moving and the pedal to keep dropping. When you release the pedal the fluid moves back. Replacing or rebuilding the master cylinder will fix this problem.

andrew lohaus

REPLACE THAT THING ASAP. a bad master cylinder will feel *ok* for normal driving, but when you realy need to hit the brakes hard, itll crap out. VERY DANGEROUS. i learned this one he hard way on my old civic.

88RX7Rag

thanks for the info everyone.

ok so i need to replace my Master Cylinder.

i'm down in coronado at a school and my mazda manuals are in oceanside so i need some info from you guys if possible.

i logged onto autozone to look for a p/n for a replacement master cylinder. there are some questions i have.

stock suspension or heavy duty? if it's stock then i'm fine it brings me right to the p/n, if it's heavy duty then it asks more questions. (this is a 88 RX7 conv. so i don't know what of those 2 options i have.)

ok if it's heavy duty then it asks: with or without anti-lock brakes....sadly i have no idea i rarely drive this car it's the wife's. I honestly don't think it has ABS, i've owned ABS brake cars before and this mazda doesn't pulse when you hold the brake pedal as far as i can tell...

last option to choose if it's without ABS is turbo or non and this one i actually know...NON.

lastly, they have 2 prices, one is for a new one with a new res, the other is for a rebuild.

Aside from the $40 price difference anyone have a recommendation as far as which to get?


thanks alot.

88RX7Rag

anyone???

I have 2 days to get this fixed before i need to head back to Oceanside i have the tools needed to fix it down here i just need to know what p/n i need.