Brake Fluid - Ford Bronco Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 23 (permalink) Old 05-10-2012, 02:57 PM Thread Starter
Registered User
 
Join Date: May 2012
Posts: 2
iTrader: (0)
Brake Fluid

I have a 1980 bronco, When I got in it today I felt very little pressure on the brakes so I poped open the Master Cylinder and its pretty low on fluid. Anyways the question is you just pour some fluid into it until its full? Also should be a certain brake fluid im buying for it?
Timtim89 is offline  
Sponsored Links
Advertisement
 
post #2 of 23 (permalink) Old 05-10-2012, 03:08 PM
Banned
 
Join Date: Jul 2003
Location: Memphis, TN
Posts: 39,390
Bronco Info: '83 VIN & title on '93 frame/body w/'95 4.9L & EB paint
iTrader: (103)
Yes, add some DOT3 fluid ASAP. Then start diagnosing WHY it's low. Is there a leak? Are the rear cables or autoadjusters stuck? Or are the front pads worn? For more info, click my black Bronco in my signature & read the captions in the Brakes & Hubs album.



Steve83 is offline  
post #3 of 23 (permalink) Old 05-10-2012, 03:10 PM
Registered User
 
Madcat455's Avatar
 
Join Date: Nov 2010
Location: Cape Coral, FL
Posts: 177
Bronco Info: 89 XLT daily driver
iTrader: (2)
Short answer... DOT3 fluid, and yea... About 1/4 from full.


Long answer... You don't "use" brake fluid, it had to go somewhere... You need to find where before you drive it. Its hard enough to stop a 6,000lb beast, you don't need to try with a busted line as well.
Madcat455 is offline  
Sponsored Links
Advertisement
 
post #4 of 23 (permalink) Old 05-10-2012, 03:12 PM
Registered User
 
Join Date: Apr 2012
Location: Mandeville, La.
Posts: 91
Bronco Info: 1989 Eddie Bauer
iTrader: (0)
The fluid went somewhere. It may be a good time to do a good inspection, correct the problems and flush the the system. I flush the fluid about every 18 months. Just my .02
Motion is offline  
post #5 of 23 (permalink) Old 05-10-2012, 03:20 PM Thread Starter
Registered User
 
Join Date: May 2012
Posts: 2
iTrader: (0)
Quote:
Originally Posted by Steve83 View Post
Yes, add some DOT3 fluid ASAP. Then start diagnosing WHY it's low. Is there a leak? Are the rear cables or autoadjusters stuck? Or are the front pads worn? For more info, click my black Bronco in my signature & read the captions in the Brakes & Hubs album.
Well the cylinder itself is around 20 years old this truck has work to do on it, My father and I havnt really had any time to work on it much but its gettin done little by little.
Timtim89 is offline  
post #6 of 23 (permalink) Old 05-10-2012, 03:39 PM
Registered User
 
deadmans bronco's Avatar
 
Join Date: Feb 2012
Location: Spokane WA
Posts: 89
Bronco Info: 1984 5.8 351w c6 np208f
iTrader: (0)
ya i got a leak to but it aint that bad i just check it every few days to make sure it is good but i think my leak is from the lid on the mc cheap ebay parts i know u get what you pay for
deadmans bronco is offline  
post #7 of 23 (permalink) Old 05-10-2012, 04:56 PM
FSM Lifetime
 
4DI2D's Avatar
 
Join Date: Feb 2012
Location: Keizer, Oregon
Posts: 243
Bronco Info: '93 Custom, '90 Lincoln TC 302, E4OD, 31s, posi front diff,QFL
iTrader: (0)
Synthetic DOT 4 works like a charm and improves the safety factor.
Only DOT 5 can't be used with any other fluid.
4DI2D is offline  
post #8 of 23 (permalink) Old 05-10-2012, 05:33 PM
Banned
 
Join Date: Jul 2003
Location: Memphis, TN
Posts: 39,390
Bronco Info: '83 VIN & title on '93 frame/body w/'95 4.9L & EB paint
iTrader: (103)
Yes, calipers "use" brake fluid temporarily. When you change the pads, the fluid returns to the MC.



Steve83 is offline  
post #9 of 23 (permalink) Old 05-10-2012, 05:46 PM
Fullsize Member
 
95bronco12's Avatar
 
Join Date: Sep 2011
Location: So~cal
Posts: 1,517
Bronco Info: 1995
iTrader: (0)
Breaks who needs em!

Deffently look around and check for leaks also check pads.
95bronco12 is offline  
post #10 of 23 (permalink) Old 05-11-2012, 06:12 AM
Registered User
 
Join Date: Apr 2012
Location: Mandeville, La.
Posts: 91
Bronco Info: 1989 Eddie Bauer
iTrader: (0)
When changing pads/shoes it bad practice to "push" the old fluid from the caliper/wheel cylinders back into the system, it's better to open the bleeder and expell the old into a container and refill the system with fresh fluid. Just my .02
Motion is offline  
post #11 of 23 (permalink) Old 05-11-2012, 10:54 AM
Roller rockers are gay
 
TheUnforgiven's Avatar
 
Join Date: Aug 2004
Location: Woodridge, Illinois
Posts: 19,200
Bronco Info: 2005 Chevrolet Venture, 1997 Acura TL, 1994 Chevy Caprice
iTrader: (11)
Quote:
Originally Posted by Motion View Post
When changing pads/shoes it bad practice to "push" the old fluid from the caliper/wheel cylinders back into the system, it's better to open the bleeder and expell the old into a container and refill the system with fresh fluid. Just my .02
no it isn't. brake fluid doesn't go bad, it just gets dirty and laden with water. that doesn't mean it won't work, it just lowers the boiling point.

you could use your own piss as brake fluid, it would just boil at a lower temperature.

and that fluid doesn't stay just in the calipers, it is fluid and will move around the system.

if the system is fine (not the case in the OP's post) without leaks or anything, there's no reason to open the system just to replace part of the fluid. full flush? fine, but just to save from pushing the fluid back up no.

2005 Chevy Venture. 1997 Acura TL. $500 beater. 1994 Chevy Caprice.
Quote:
Originally Posted by "Bronco" John Galt View Post
New nuts are in the plan.
"Kids, they see the good in everything and through their eyes, they open ours." - Hank Davis

"To be easily amused is to live most of your life smiling."
TheUnforgiven is offline  
post #12 of 23 (permalink) Old 05-11-2012, 11:06 AM
Registered User
 
Madcat455's Avatar
 
Join Date: Nov 2010
Location: Cape Coral, FL
Posts: 177
Bronco Info: 89 XLT daily driver
iTrader: (2)
Quote:
Originally Posted by TheUnforgiven View Post
no it isn't. brake fluid doesn't go bad, it just gets dirty and laden with water. that doesn't mean it won't work, it just lowers the boiling point.

you could use your own piss as brake fluid, it would just boil at a lower temperature.

and that fluid doesn't stay just in the calipers, it is fluid and will move around the system.

if the system is fine (not the case in the OP's post) without leaks or anything, there's no reason to open the system just to replace part of the fluid. full flush? fine, but just to save from pushing the fluid back up no.
Would ABS be an exception to this?? I've heard from several mechanics that it's a bad practice to push fluid backwards through the ABS module...
Madcat455 is offline  
post #13 of 23 (permalink) Old 05-11-2012, 11:12 AM
Roller rockers are gay
 
TheUnforgiven's Avatar
 
Join Date: Aug 2004
Location: Woodridge, Illinois
Posts: 19,200
Bronco Info: 2005 Chevrolet Venture, 1997 Acura TL, 1994 Chevy Caprice
iTrader: (11)
i've never opened a caliper to expel the fluid when replacing the pads, ABS or not. Ever. I've never seen anyone else do that either.

think about it, fluid moves through it to the calipers when you apply the brakes, when you RELEASE the brakes, the fluid flows backwards through the pump/module back to the master cylinder. which is exactly the question you asked. it does that ALL the time every day, every stop. you won't hurt anything.

2005 Chevy Venture. 1997 Acura TL. $500 beater. 1994 Chevy Caprice.
Quote:
Originally Posted by "Bronco" John Galt View Post
New nuts are in the plan.
"Kids, they see the good in everything and through their eyes, they open ours." - Hank Davis

"To be easily amused is to live most of your life smiling."
TheUnforgiven is offline  
post #14 of 23 (permalink) Old 05-11-2012, 12:11 PM
Registered User
 
Join Date: Apr 2012
Location: Mandeville, La.
Posts: 91
Bronco Info: 1989 Eddie Bauer
iTrader: (0)
Think about it, the volume of fluid used when applying the brakes(thousands of an inch) is way less then the volume of fluid pushed back when replacing the pads (thickness of the new pads). And yes I do believe in changing the fluid (pressure bleeding only) every 18 months regardless weather or not I've worked on the system. Just my .02
Motion is offline  
post #15 of 23 (permalink) Old 05-11-2012, 12:37 PM
Banned
 
Join Date: Jul 2003
Location: Memphis, TN
Posts: 39,390
Bronco Info: '83 VIN & title on '93 frame/body w/'95 4.9L & EB paint
iTrader: (103)
Quote:
Originally Posted by Motion View Post
When changing pads/shoes it bad practice to "push" the old fluid from the caliper/wheel cylinders back into the system...
Not according to Ford.
Quote:
Originally Posted by Motion View Post
...it's better to open the bleeder...
That's how you get contamination & air into the system: by opening it unnecessarily. Don't.
Quote:
Originally Posted by Madcat455 View Post
Would ABS be an exception to this?? I've heard from several mechanics that it's a bad practice to push fluid backwards through the ABS module...
Not in Ford HCUs, but MOST other brands (especially GM) can be totally destroyed by pushing fluid backward. So almost all OTHER brands of vehicle w/ABS require that the bleeders be opened when changing pads. But never Fords; ABS or not.



Steve83 is offline  
post #16 of 23 (permalink) Old 05-11-2012, 02:13 PM
Registered User
 
Join Date: Apr 2012
Location: Mandeville, La.
Posts: 91
Bronco Info: 1989 Eddie Bauer
iTrader: (0)
Quote:
Originally Posted by Steve83 View Post
That's how you get contamination & air into the system: by opening it unnecessarily. .
The system is open to atmosphere thru the vent int the master cylinder cap, which is why periodic flushes are necessary. Just my .02
Motion is offline  
post #17 of 23 (permalink) Old 05-11-2012, 05:19 PM
Former owner of Shadofax
 
Shadofax's Avatar
 
Join Date: Jun 2003
Location: where havn't I lived? Now in Erie, CO
Posts: 17,038
Bronco Info: 95XLT351 E4OD SAS 44/ARB/Alloy shafts-joints. D60 rear/Detroit. 4wheel disc,35" KO2's, 4.56etc.
iTrader: (17)
Quote:
Originally Posted by Motion View Post
The system is open to atmosphere thru the vent int the master cylinder cap, which is why periodic flushes are necessary. Just my .02
I don't believe the cap is vented.

______________________
Click my supermotors link for tech on TCase, SAS, OBA, Soft Top, Overhead Console, Stock bumper Winch install, much more..:
http://www.supermotors.net/registry/628



Shadofax is offline  
post #18 of 23 (permalink) Old 05-11-2012, 05:33 PM
FSM Lifetime
 
4DI2D's Avatar
 
Join Date: Feb 2012
Location: Keizer, Oregon
Posts: 243
Bronco Info: '93 Custom, '90 Lincoln TC 302, E4OD, 31s, posi front diff,QFL
iTrader: (0)
If the m/cyl cap wasn't vented it would blow off the top when you put the jumbo screwdriver in to push the caliper pistons back!
4DI2D is offline  
post #19 of 23 (permalink) Old 05-11-2012, 05:41 PM
Former owner of Shadofax
 
Shadofax's Avatar
 
Join Date: Jun 2003
Location: where havn't I lived? Now in Erie, CO
Posts: 17,038
Bronco Info: 95XLT351 E4OD SAS 44/ARB/Alloy shafts-joints. D60 rear/Detroit. 4wheel disc,35" KO2's, 4.56etc.
iTrader: (17)
Quote:
Originally Posted by 4DI2D View Post
If the m/cyl cap wasn't vented it would blow off the top when you put the jumbo screwdriver in to push the caliper pistons back!
I don't know about the jumbo screwdriver, I use a c clamp, but that makes sense, except it seems to me the cap must be pressure activated, meaning after a certain amount of pressure in pressing the pads in and forcing fluid back into the MC it would open and begin to vent. But I don't think it's just "vented". So the only time it would be vented would be when doing brakes, which is when you're opening the cap to play with fluid level anyway.

Edit: I guess it's the cap diaphragm that allows this....."Further, energy is required to open the vent, which results in brake fluid movement delay. Also, brake fluid can leak out through the vent slit."

______________________
Click my supermotors link for tech on TCase, SAS, OBA, Soft Top, Overhead Console, Stock bumper Winch install, much more..:
http://www.supermotors.net/registry/628



Shadofax is offline  
post #20 of 23 (permalink) Old 05-12-2012, 12:00 AM
Banned
 
Join Date: Jul 2003
Location: Memphis, TN
Posts: 39,390
Bronco Info: '83 VIN & title on '93 frame/body w/'95 4.9L & EB paint
iTrader: (103)
DOT3 brake fluid is EXTREMELY hygroscopic, so it's NOT vented. Of course, there's a safety release like the A/C system has, but that doesn't qualify as a "vent", either.

As fluid moves into the calipers due to pad wear, the diaphragm in the cap follows the fluid level down, maintaining a seal between the outside air & the fluid. When you compress the calipers, that fluid moves back to the reservoir. So as long as you have NOT added fluid since the last pad change, it won't overflow the reservoir.



Steve83 is offline  
Sponsored Links
Advertisement
 
Reply

  Ford Bronco Forum > Bronco Discussions > Noobie Bronco Tech Questions. Flame free zone!

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Bronco Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself. DO NOT USE Gmail.com accounts. If you only have a Gmail.com email please contact the administrator here

Email Address:
OR

Log-in










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



Posting Rules  
You may post new threads
You may 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