View Full Version : '80 hilux brake master cyl

09-08-2012, 03:46 PM
I was wondering if anyone knows a good method to test the master cylinder? My pedal is doing the "slow drop to the floor", but I'm not losing any fluid based on the reservoir level and there does not appear to be any leakage anywhere else. The shoes and pads are somewhat worn, but not to the point they need replacement yet. I'm thinking master cylinder is failing, but wanted to do any tests possible before buying new parts.

I have misplaced my manual. Any tips appreciated. :hill:

09-08-2012, 03:55 PM
That's the test, pressure on the pedal and if it sinks it's faulty. Do it with the engine off otherwise it's inconclusive between the MC and the booster, with no boost the pedal should be very firm and have no movement. Toyota calls the pedal movement after the pads and shoes engage "reserve travel" I think and the spec is like 3mm. Sounds like to me it's bad.

09-08-2012, 04:17 PM
Thanks Dave. I tried it with the engine off and there seemed to be no drop and very firm. Would that indicate booster?

09-09-2012, 11:50 AM
if it sinks, it meens that there could also be air in the system. but how did it get there ?
what are the measurments of the brakes ? if the rotors and drums have been resurfased to many times without being measured they can be well beyond service limit. therefor even with the pads still at 1/2 life the calipers can still be beyond working limit.. causing what your fealing.

i would reccomend bringing it to any shop and have a FREE brake inspection.
i work at a shop on the south west side if your this way.
any good shop will measure all your rotors and drums, all the pads and shoes, inspect the calipers and wheel cylenders, insure good brake ballance, and check all the hoses and hardware.

if your brake pads or shoes are cracked or "cracking" then it will feal like a soft un responsive pedal. (not a droping pedal like your's but soft and less responsive)

09-10-2012, 01:41 PM
Thanks Tim, guess I'll take it in and get it checked out. It could be out of spec, so no use chasing my tail trying to troubleshoot.

09-10-2012, 05:46 PM

09-10-2012, 06:10 PM
Didn't Randy have a similiar issue and figured out that it was the old brake lines? The rubber was starting to get aged and was expanding under pressure. Just a thought...

09-10-2012, 11:44 PM
That is exactlly what happens with old "rubbers" the main issue is that almot EVERY shop will NOT replace hoses unless they are visually leaking. Which I highlly dissagree with (even my current shop is like that, as were the last 3 shops I worked at ) becaus the failure is internal and your it going to always see it.

09-14-2012, 03:30 PM
Called Toyota stealership and the brake master cylinder is no longer available. :(

and it was listed at $230..:eek:

Local Napa had an aftermarket unit on the shelf for $66. :thumb: