Brake Booster leaking

[salomon68]

I was bleeding my brakes and brake fluid started leaking out of the junction between the booster and the master cylinder. I already tightened it down but you can still hear a tiny leak (quiet hissing sound). Any pointers on replacing that seal? Is there anything that should be replaced while I have it apart?

I just installed SS lines front and rear along with rotors, new calipers, new pads etc.

 

[barkz]

master cylinder rebuild kit(rear most seal is probably junk). the fluid is coming from the master, not your booster(at least i hope it not lol).

 

[mkiiichip]

They are not worth rebuilding, replace it with an genuine ASIN brand.

 

[Satan]

The booster will need to replaced with a used/rebuilt, if it is leaking. No rebuild kit with that diaphram that I know of.

Master rebuild kit was about $12 (had to order & wait 1 day). Simple enough to rebuild and the TRSM covers it too. You still need the factory recommended grease (look in the TRSM). I think an already rebuilt master cyl. was about $55 and I would've still had to order it.

I guess what you can do will depend on the issue/factors you find... master is bad, booster is bad, need right away/order... I'd go ahead and rebuild the master, after all the work you've done. If it's never been replaced and is not bad now, it will be soon after all of the upgrades/improvements you've done elsewhere in the brake system.

 

[salomon68]

Well, the brakes worked fine before I got the car a couple of years ago and started a complete overhaul of just about everything. It looks like there is a seal there where those 4 bolts/nuts attach the master cylinder to the booster (assuming that it is the round black thing). It's leaking out between the two bottom bolts/nuts.

 

[hvyman]

Fluid should not be going into the booster.

 

[Satan]

There's usually a paper gasket between the master cyl and booster, but it's not a "leak preventor." If fluid/air is leaking, it's likely things getting past the piston/seals in the master.

 

[salomon68]

There's usually a paper gasket between the master cyl and booster, but it's not a "leak preventor." If fluid/air is leaking, it's likely things getting past the piston/seals in the master.

Cool. That helps a lot. So I guess I need to either buy a new master cylinder or get a rebuild kit. Some guy earlier said that it wasn't worth rebuilding, how true is that?

 

[airhead04]

http://store.driftmotion.com/static/i-brakemastercylinderrebuildkit865to90mk3wabs.php

http://store.driftmotion.com/static/i-brakemastercylinderrebuildkit90-92mk3wabs.php

There you are man.

 

[mkiiichip]

Some guy earlier said that it wasn't worth rebuilding, how true is that?

Some guy? lol

They are not hard to rebuild, its just that rebuilt ones dont last as long.
You can rebuild it for $80, or you can get a new OEM one for $100.
The new one has all new parts, you decide.

And by OEM i mean ASIN brand, not that you have to buy it from toyota.
http://www.autopartswarehouse.com/d...Master_CylinderQQ19861992QQW0133-1617257.html

 

[salomon68]

Ordering the new ASIN OE brake master cylinder now. Thanks for the help!