Disappearing brake fluid, but not leaking anywhere. - Toyota Nation Forum : Toyota Car and Truck Forums
Pre-88 Toyota Pickup/Hilux Discussion area for the '88 and older Toyota Pickup/Hilux.

 3Likes
  • 1 Post By Wekadog
  • 1 Post By Blackness
  • 1 Post By Blackness
 
LinkBack Thread Tools Display Modes
post #1 of 10 Old 05-15-2019, 10:54 AM Thread Starter
Wanna Fix It!
 
John Anthony's Avatar
 
Join Date: Mar 2010
Location: Near San Antonio, TX
Posts: 3,801
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Thanks: 326
Thanked 483 Times in 424 Posts
Lifetime Supreme Member
iTrader Score: 0 reviews
(Thread Starter)
Disappearing brake fluid, but not leaking anywhere.

I keep having to add brake fluid to the master cylinder reservoir periodically when the "brake" light in the dash is illuminated. I've checked the wheel cylinders and calipers and they are not leaking. The master cylinder and reservoir are dry on the outside, so no leaks there. It's been doing this for quite a while. Where is the brake fluid going?


The brakes operate normally, EXCEPT on long trips over an hour during which the pedal goes to the floor occasionally. A 2nd pump of the pedal and all is normal for a while. When driving local errands I have no issue with the brakes......only on long trips.

.



2004 Corolla LE 375K+ miles.
1987 Toyota Pickup base, 4spd 162K+ miles.
1996 Toyota Camry LE I4 (son's car) 230K+ kilometers.
2010 Toyota Camry LE I4 (mother's car). 162K+ miles.



"There's always free cheese in a mousetrap."
John Anthony is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 05-15-2019, 02:23 PM
Official TN Member
 
Join Date: Sep 2012
Location: Ventura Co, California USA
Posts: 376
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Thanks: 5
Thanked 42 Times in 41 Posts
iTrader Score: 0 reviews
How long is it between top-ups? It's normal to need more fluid as the calipers and wheel cylinders push outward compensating for wear. If it's just once in six months, or if you're heavy on the brakes, it might be normal/


If you're needing to top up weekly or monthly with normal driving, that's a bit much. Could the fluid be leaking out the piston end of the master cylinder? You would have to remove it to find a leak there.
John Anthony likes this.

Last edited by Wekadog; 05-15-2019 at 02:28 PM.
Wekadog is offline  
post #3 of 10 Old 05-15-2019, 10:18 PM Thread Starter
Wanna Fix It!
 
John Anthony's Avatar
 
Join Date: Mar 2010
Location: Near San Antonio, TX
Posts: 3,801
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Thanks: 326
Thanked 483 Times in 424 Posts
Lifetime Supreme Member
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by Wekadog View Post
How long is it between top-ups? It's normal to need more fluid as the calipers and wheel cylinders push outward compensating for wear. If it's just once in six months, or if you're heavy on the brakes, it might be normal/


If you're needing to top up weekly or monthly with normal driving, that's a bit much. Could the fluid be leaking out the piston end of the master cylinder? You would have to remove it to find a leak there.
I'm not heavy on the brakes and I hardly drive this truck at all. Maybe 2K miles per year. It's definitely much, much more than normal compensation for wear. When you say "leaking out the piston end of the master cylinder", do you mean where it connects to the vacuum booster? I've only once replaced a master cylinder, and that was on a 1997 Camry. If it's leaking from the piston end, does that mean it's leaking into the booster? If so, does that mean the booster is bad, or does that mean the master cylinder is bad?

.



2004 Corolla LE 375K+ miles.
1987 Toyota Pickup base, 4spd 162K+ miles.
1996 Toyota Camry LE I4 (son's car) 230K+ kilometers.
2010 Toyota Camry LE I4 (mother's car). 162K+ miles.



"There's always free cheese in a mousetrap."
John Anthony is offline  
Sponsored Links
Advertisement
 
post #4 of 10 Old 05-15-2019, 10:38 PM
Official TN Member
 
Join Date: Sep 2012
Location: Ventura Co, California USA
Posts: 376
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Thanks: 5
Thanked 42 Times in 41 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by John Anthony View Post
. . . "leaking out the piston end of the master cylinder", do you mean where it connects to the vacuum booster? . . . does that mean it's leaking into the booster? If so, does that mean the booster is bad, or does that mean the master cylinder is bad?
If fluid is leaking from the master cylinder, the MC is bad. The fluid could be pooling up inside the booster.

You might like to remove the MC to look for signs of fluid leakage. At that point, it makes sense to disassemble and inspect the MC. If it's just corrosion, a good cleaning might fix your issue. If the seals are worn or dried, you'll need to change them, or just fit a new MC.
Wekadog is offline  
The Following User Says Thank You to Wekadog For This Useful Post:
John Anthony (05-16-2019)
post #5 of 10 Old 05-16-2019, 12:34 AM
☻Black Member
 
Blackness's Avatar
 
Join Date: Jun 2015
Location: Mojave Desert
Posts: 1,427
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 610 Post(s)
Thanks: 5
Thanked 167 Times in 158 Posts
iTrader Score: 0 reviews
^ yess.. check the massa cylinder... leaks internally









John Anthony likes this.

1995 2.2L Camry 5sfe engine
Blackness is offline  
post #6 of 10 Old 05-16-2019, 08:48 AM Thread Starter
Wanna Fix It!
 
John Anthony's Avatar
 
Join Date: Mar 2010
Location: Near San Antonio, TX
Posts: 3,801
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Thanks: 326
Thanked 483 Times in 424 Posts
Lifetime Supreme Member
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by Wekadog View Post
If fluid is leaking from the master cylinder, the MC is bad. The fluid could be pooling up inside the booster.

You might like to remove the MC to look for signs of fluid leakage. At that point, it makes sense to disassemble and inspect the MC. If it's just corrosion, a good cleaning might fix your issue. If the seals are worn or dried, you'll need to change them, or just fit a new MC.
Quote:
Originally Posted by Blackness View Post
^ yess.. check the massa cylinder... leaks internally

Will remove it and see. I've got too much on my plate currently, but will report back here whenever I get to this. Thanks Wekadog and Blackness.

.



2004 Corolla LE 375K+ miles.
1987 Toyota Pickup base, 4spd 162K+ miles.
1996 Toyota Camry LE I4 (son's car) 230K+ kilometers.
2010 Toyota Camry LE I4 (mother's car). 162K+ miles.



"There's always free cheese in a mousetrap."
John Anthony is offline  
post #7 of 10 Old 05-16-2019, 10:09 PM Thread Starter
Wanna Fix It!
 
John Anthony's Avatar
 
Join Date: Mar 2010
Location: Near San Antonio, TX
Posts: 3,801
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Thanks: 326
Thanked 483 Times in 424 Posts
Lifetime Supreme Member
iTrader Score: 0 reviews
(Thread Starter)
I decided to take another look at the wheels before removing the master cylinder. It's possible I was mistaken and now I think my rear driver's wheel cylinder is leaking. I noticed the paint on the backing plate was all peeling and damp, which is something brake fluid can do (removes paint). I decided to take the drum off to take a look-see. Can't get the drum off, though. Will try again tomorrow. Will let ya'll know.

.



2004 Corolla LE 375K+ miles.
1987 Toyota Pickup base, 4spd 162K+ miles.
1996 Toyota Camry LE I4 (son's car) 230K+ kilometers.
2010 Toyota Camry LE I4 (mother's car). 162K+ miles.



"There's always free cheese in a mousetrap."
John Anthony is offline  
post #8 of 10 Old 05-16-2019, 11:26 PM
☻Black Member
 
Blackness's Avatar
 
Join Date: Jun 2015
Location: Mojave Desert
Posts: 1,427
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 610 Post(s)
Thanks: 5
Thanked 167 Times in 158 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by John Anthony View Post
I decided to take another look at the wheels before removing the master cylinder. It's possible I was mistaken and now I think my rear driver's wheel cylinder is leaking. I noticed the paint on the backing plate was all peeling and damp, which is something brake fluid can do (removes paint). I decided to take the drum off to take a look-see. Can't get the drum off, though. Will try again tomorrow. Will let ya'll know.
- retract the shoes a bit to get the drum off
- then manhandle it a bit
- glad you found the problem!
















.
John Anthony likes this.

1995 2.2L Camry 5sfe engine
Blackness is offline  
post #9 of 10 Old 05-27-2019, 08:39 PM Thread Starter
Wanna Fix It!
 
John Anthony's Avatar
 
Join Date: Mar 2010
Location: Near San Antonio, TX
Posts: 3,801
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Thanks: 326
Thanked 483 Times in 424 Posts
Lifetime Supreme Member
iTrader Score: 0 reviews
(Thread Starter)
Finally got the drum off, which you can read about in the other thread. Anyway....

Yes, the leak was now obviously coming from the rear driver's side. You can see all the greasy muck:





I'm going to replace everything (maybe reuse the drums if I can get them resurfaced). I'm going to use Advics wheel cylinders. Can anybody recommend a brand for the other parts like the hardware kit, self-adjuster repair kit, and shoes?

.



2004 Corolla LE 375K+ miles.
1987 Toyota Pickup base, 4spd 162K+ miles.
1996 Toyota Camry LE I4 (son's car) 230K+ kilometers.
2010 Toyota Camry LE I4 (mother's car). 162K+ miles.



"There's always free cheese in a mousetrap."
John Anthony is offline  
The Following User Says Thank You to John Anthony For This Useful Post:
BamZipPow (05-27-2019)
post #10 of 10 Old 05-27-2019, 09:40 PM
イリジウム
 
Join Date: Apr 2009
Location: Calif
Posts: 11,419
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 1021 Post(s)
Thanks: 364
Thanked 1,435 Times in 1,355 Posts
Supreme Member
iTrader Score: 0 reviews
Try Bendix (rockauto has some close out deals) Carlson or Centric.
JohnGD is offline  
The Following User Says Thank You to JohnGD For This Useful Post:
John Anthony (05-27-2019)
Sponsored Links
Advertisement
 
Reply

  Toyota Nation Forum : Toyota Car and Truck Forums > Toyota Truck, SUV and Van Forums > Hilux (Pickup) Forum > Pre-88 Toyota Pickup/Hilux

Bookmarks

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome