As I was driving today my brakes decided to play games with me,one minute they wanted to work then they didn't. I pumped them a couple of times it went back to working, as I was trying to park at walmart the brake pedal goes straight to the floor, got it stopped and park. Went inside to Wally World got what I needed then left. I popped the hood checked my brake fluid it was full, looked underneath no leaks. Hopped in to go, the brakes are still to the floor so I pump them some more got it good enough to make it home just making sure I wasn't behind anyone too close, they did ok on the way home again when I went to park at the house they went out, luckily I had a fence to help stop me (no scratches and the fence is tough) Any ideas on what's going on?
Hopefully this isn't a stupid question, still learning my way around in the mechanic world

 

I would start off by bleeding the brakes and seeing if that helps at all. You may have some air in the system.

 

Hmmmm I did a good bleed the first time I bled them BUt we can bleed them again. She has drove it about 1000 miles with no problems with brakes till now.

History: Replaced calipers, Wheel cylinders, all pads and shoes, and rear brake line. 1000 miles ago

Brakes have been the touchiest brakes ever you barely hit them and you are stopping quick. Now it has started acting up. I will attempt to rebleed, them but am curious how it will act if it is in fact the brake booster going out.

 

I would try the bleed first before putting money into it.

 

I agree with re-bleeding the system and if you still have the same issue the master cylinder is a strong possibility. I had an MC go bad internally and it didn't leak but it was like the pressure pushed right through.

 

Yeah that is a given, Will get to it when I get home from work. Tess good job on creating a thread and being pretty good at explaining your problem. I applaud you

 

Thanks for the help guys! Rob Hurry up get here I am ready to get to work

 

Let us know how it work out, but my best guess would be air in the lines.

 

Let us know what you find Tess/Rob!!!

 

So far all I have found is a coolant leak coming from under the exhaust manifold. Freeze plug or head gasket. One drop a minute so it aint bad YET.

Brakes well they are spongy now. No brake leaks anywhere I just went and bought some more brake fluid I will either mess with hers tonight or tomorrow. I am so close to having mine done that I am neglecting hers now.

 

Drivin the mall crawler are ya!!

Could the MC be leaking fluid past the piston? Or leaking into the booster? Just things to consider. HTH. Keep us up to date.

 

Might be worth checking the rear brake setup. I had a few brake issues regarding the rear wheel cylinder. They leak sometimes......

 

Not losing any fluid and they are brand new cylinders.

I finished my truck up so I will play with her tomorrow. I will start with removing all the fluid from the master cylinder then cleaning it out real good since it is gunky. Then put new fluid in it and do a good bleed. If I have no luck then I will start checking the brake booster.

 

if theyre weak most likely its got a leak, dont just bleed your brakes look through all the lines and try to find a leak, if you find one fix it and then bleed them

 

I would imagine that doing what you plan on doing will solve the problem.