I noticed my brake pedal starting to get mushy so I looked at the master cylinder. It looks like it has started leaking. I remember reading somewhere that you can replace the seals and it will be good as new. Is that the case? If so can anyone describe the process or offer any hints? All input is appreciated.

Thanks, Matt

You can purchase a new master cylinder or a rebuild kit. I would stick with Aisin if possible.

Consider rebuilding the wheel cylinders at the same time as the seals will probably be blown out with a revitalized master cylinder.

There's not much to rebuilding the master cylinder. Remove it from the booster, drain the fluid, and pull out the guts. Check over the bore for rust and pitting. Get the cylinder hone tool from NAPA to clean up the bore as necessary, but more than very minor pitting will probably require a new master.

Dip new guts in brake fluid before install. Bleed from furthest wheel back after bench bleeding the master. Don't forget the LSPV if equipped.

Hey Cruiser,
What is the LSPV. All I know is it is associated with the brakes. Some people say it needs to be adjusted sometimes. I adjusted and replaced many brake parts on my 92 4Runner but have never ran into the LSPV. Thanks
Sid

LSPV= Load sensitive proportioning valve. It adjusts the effectiveness of the rear brakes by measuring the distance between the frame and axle with a rod. I think its only on trucks but i'm not sure.

Thanks a lot for the tips cruiserman.

I bought the master cylinder rebuild kit from Toyota and rebuilt it myself. It's easy to do as long as your mc isn't scored inside. Go check www.1sttoyotaparts.com for the rebuild kit, I think it's around $37.