Hi guys,
Yesterday I was out driving my 2000 4Runner and noticed that my brake pedal had loss substantial pressure. It felt like I had a brake fluid leak, so I quickly stopped and checked for leaks but could not find any. I noticed that I could build up pressure by pumping my brake pedal, so I was able to drive home safely.

Do I need to replace my entire master cylinder? Any advise is appreciated.

I drive my car everyday, and it has approx. 170,XXX miles on it. I say “approximately” because my digital odometer went out a while ago.

Thanks in advance,

Marcelo

 

2000 has a digital odometer? Interesting. I thought they were all manual until the 4th gen

If you're losing fluid, the e-brake light will come on and stay illuminated. This basically operates as an idiot light for the brake system. If it's not illuminated, it's not a fluid issue.

 

I would say the master is a good place to start. If you had an external leak somewhere, the pedal would probably continue to drop and you applied pressure.


'99 was the first year for digital odometers.

 

Thank guys... I have confirmed that I'm not leaking any brake fluid anywhere externally... so it's definitely my master cylinder.
I'll be getting a new master cylinder part #47201-3D380 (see image below). I just want to make sure I'm getting the correct part.
Is there anything else I should replace while doing this job?

Thanks for all your help guys,

 

Never a bad idea to replace the release cylinder at the same time. And you'll want a bleed kit if you don't already have one.

I think Tacomas are different, but my 98 has a digital odometer.

 

My '01 showed exactly 2 miles on its digital odometer on June 23, 2001 (day I purchased it).
Now shows 497,500....



Andreas

 

I would insure your rear drum to shoe distance is set as per FSM and that you have a functioning ebrake, if these two things are not set or working correctly you will, or soon will have excessive pedal travel and only front brakes that will eventually warp from over use.

 

I could be wrong, but don't the rear brakes "self adjust" when you back up, and apply the brakes hard? I thought I read that in the FSM for the 87's I have, but I may be wrong. I'll see if I can dig it up. I think it only does it if the shoes are adjusted too loose to start with, and then as they wear down, but I might be wrong again.

I'll see what I can find...
Pat☺

Edit: Here's the page out of the FSM for 86-89 trucks, 4Runner in particular. The system for the 3rd gen trucks is very similar, just upside down. IE: at the top. It looks to me, although there's no description, that the newer system functions with the application of the parking brake, possibly while moving in reverse. Although perhaps not. I'm not sure. I'll keep digging.

 

The 3rd gen is totally different, you would want to adjust it so the drums just slip over the shoes, and then it needs to be adjusted manually when setting up drum to shoe clearance, this can be checked and adjusted by removing the 2 rubber plugs on the back of the dust shield, a couple ebrake pulls to check bellcrank, and then the casual use of the ebrake will make the minor adjustments needed throughout the majority of the shoes lifespan. This is critical for proper brake operation on these trucks and likely why many have warped front rotors or suspect and cause master brake cylinder issues and then think they need the TBU upgrade, I’ve never felt the need for the TBU on any of the x3 3rd gen 4R’s even with 33”x12.5” tires, lifted and pulling a large pop-up camper as long as the drums & ebrake where working properly.
http://www.teamtoyota4x4.org/archivi...r/rdb/inst.pdf