K folks... I'mma replace my master cyl. this weekend... Lookin' at my Alldata it says use only DOT3 fluid but I'mma be flushing it ALL out and a new Master Cyl. so should I use DOT4???

 

An excerpt I found for ya.

Don't take a break from brake maintenance
Aftermarket Business, April, 2005 by Jay Buckley
Brakes need to be maintained on a regular basis. In an age when many new vehicle ads create the impression that modern cars and trucks need little upkeep, if any, this may surprise some consumers.

Though not every automaker lists it in their maintenance manual, flushing and replacing brake fluid is an important preventive maintenance procedure. Regular inspections and proper lubrication also help prevent brake system problems.

Q How often and why should brake fluid be flushed and replaced?

A Typical manufacturer recommended intervals are two to three years regardless of vehicle mileage, as moisture can accumulate in a brake hydraulic system over time whether the vehicle is parked or driven.

To help prevent water from accumulating, DOT 3 and DOT 4 brake fluid disperse dampness throughout the entire hydraulic system. If brake fluid is flushed and replaced before it has become saturated, or "wet," the moisture does little damage. However, after two or three years, brake fluid can become saturated. When this happens, the fluid is unable to absorb any additional water, which instead may "precipitate" into droplets. This can cause hydraulic system parts to deteriorate from the inside, which is especially costly when ABS components are involved.

An additional, serious consequence of wet brake fluid is that it boils at a lower temperature than it does when fresh. That's bad news for any driver, because the brakes can fail, either partially or completely, if the brake fluid boils. Consider the heat generated by brakes of an SUV towing a trailer through the mountains in the summer and it is easy to see the potential, grave consequences of boiling brake fluid--and how brake fluid boiling is not a far-fetched situation.


Q What is the difference between DOT 3 and DOT 4 brake fluid?

The biggest difference between DOT 3 and DOT 4 brake fluid is their boiling point temperatures. DOT 4 has higher wet and dry boiling points than DOT 3.

However, not all systems designed to use DOT 3 brake fluid will work well with DOT 4. For example, Hyundai prohibits using DOT 4 brake fluid in some of their DOT 3 supplied systems. Meanwhile, DOT 3 fluid should never be used in a DOT 4 system because of its lower boiling point.

 

Hey Rich, sorry I didn't get a chance to reply to your PM today....for some reason BF would not load up at work today. Anyway as far as brake fluid goes I've always been told to only use what was originally installed by the manufacturer. That is a very interesting article that lowlife posted, I've never flushed a brake system....lol.....maybe I should start doing that. I don't do hardly ANY brake work. The shop I work for specializes and I get mostly electrical stuff, interior trim, HVAC 4x4 concerns etc.., but I don't think there are any special tools to bleed your brakes out. Just bench-bleed your new master cylinder and then install it and bleed your brakes starting at the right rear and work your way toward the master cylinder. these newer cars that I typically see are different though, you don't "pump and hold and pump and hold" you open the bleeder and slowly press the pedal to the floor tighten bleeder release pedal wait 15 seconds and repeat. Probably a little more info than you needed, but that's just me.

 

yeah I know they want ya to wait... I think it's because of the short throw on these things so the piston in them is HUGE. So they want ya to wait to let any bubbles that may have been purged into the master cyl. to float up outta the way so they're not sucked right back in...
As far as the special tool goes... I called a couple dealerships until I got a tech that knew what he was talkin' about. Granted most of them were right but none of them could tell me "WHY" or "HOW" and that's KEY for me man....:P

Here's the scoop as far as that ABS module goes. There's little valve bodies inside that thing or resivoirs you might call them that are locked off during a normal braking session. They're never really exposed to the normal braking system and fluid until a ABS braking situation takes place. Now the guy told me that you DO use that tool if you're only doin' a ABS module replacement and that lets you use the bleeders ontop of the module and bleed only that in system and don't have to bleed out the entire system. but since I'm bleeding out the whole system. he said as long as I'm doin' all 4 wheels.. they'll slide back and forth so by breakin' the closed system it'll let the valve slide to the open position for that one cause there's no tension on it the acutal pressure of the fluid will move it open... when all wheels are closed off... then they pump up per say I guess. So when I lock that wheel off and go to the next one on the same end of the vehicle (front or back) it will slide over to the other side when that other wheel is opened up. And no you don't have to go front to back you still do the normal farthest from cyl. and around the vehicle until you get to the last one (under the cyl).


Just a FYI.

And yeah... I wasn't quittin' until I got an answer yesterday. I'm just an ******* when it comes to doin' stuff like that right when it's my g'friend and 3 kids in the back seat... now ME... hahhahahaha
I've driven cars with no seat in them sittin' on a milk crate and usin' the emergency brake to stop.....hahahahahahaha


Thx. folks,

 

Good info.

I am like you. Although I have used reverse to stop when the brakes went out. Oh to be young again.

 

hahahhahaha

Gotta know those clutches LOVED you......