Brake fluid flushing

[aldive]

Do you flush your brake fluid? How often? What technique? Why do you flush the brake fluid?

Thanks ......

 

[Aussie Explorer]

The breaks fluid should be done every 2 years as it gets dirty and will pick up water over time.

You can bleed the break lines and callipers at home with ABS breaks but you must be careful as if any air gets into the master cylinder or the “HCU” unit then it need’s to be taken to a dealer to have the system bleed with a special and Expensive tool as I understand it.

So the break lines and callipers can be bled in the conventional manor but not the master cylinder or HCU unit.

It is probably best just to get the dealer to do this job.

General overview>
There are little bleeder valves at each calliper (Don’t know exactly where as I have never done it on a Explorer for the above resin).

But it’s just a matter of pumping the pedal a few times to get some pressure in the system then holding it on the floor (You need 2 people). Attach a length of hose to the bleed valve one at a time starting at the rear right, with the other end of the hose submerged in some break fluid (To stop air getting into the system). Crack the valve and allow the fluid to run out (Watching for air bubbles at the submerged end of the hose) as the fluid flow slows close the valve and move to the next one, and repeat the operation.

*Remembering to top up the master cylinder reservoir as you go. You do not want air getting into the system or HCU!!

It’s been about 3 years since I have done a break bleed and it wasn’t on a Ford or a Explorer so sorry if it’s a little vague.

 

[ExplorerDMB]

We have a vacuum type pump that we use at work. It flushes all the fluid out. Anyway -- here is another post I did in another thread:

http://www.explorerforum.com/forums/showpost.php?p=1278777&postcount=8

Brake fluid does get pretty nasty. I'd do it as stated above, every two years.

-Drew

 

[rblais]

Aldive-I just bled the brakes on my 2000 Mountaineer. I used the gravity method with help from one of those small plastic hand vacuum pumps you can get at any parts store for little money. The pump I have has a small, clear plastic container attached to it and a release trigger. The tool makes it a one man job-easily. The procedure is to fill brake reservoir with clean fluid and start pulling old fluid from furthest wheel-rear right- and then working from one wheel to the next progressing towards the master cylinder. To start, break the fitting lose on caliper and retighten enough so it doesn't leak and can be worked easily. Make sure the brake reservoir is full. Pump vacuum in the tool and attach it to the fitting with the clear plastic hose. Then loosen fitting and slowly release vacuum. The fluid is sucked from the line into the vacuum jar attached to the pump. You'll see when fluid is running clear through the plastic hose. Works great. No backflow, no air, no mess. Repeat this process for the remaining wheels always keeping the reservoir full. If you find the reservoir is overfilled after bleeding the brakes you can remove some of the fluid with the vacuum pump. This is deffinately the best method I've found to bleed brakes. Good luck.

 

[gijoecam]

If the system is already full, a gravity bleed is a quick, simple method.... just crack the bleeder and let it run until it runs clear again, and you should be good.

Vacuum bleeding by sucking on the bleeders can be a bit of a pain.... I always end up sucking air in from around the threads, so it makes it difficult to determine when (or if) the air in the system is out.

Pressure-bleeding is good, especially if all you're trying to do is freshen up the fluid.

Also, don't replace the DOT3 or DOT4 fluid with DOT5 Silicone.... it will cause problems.

-Joe

 

[Lee S.]

One tip is to suck out most of the old fluid from the master cylinder (use a turkey baster) and refill with fresh fluid before bleeding.

 

[MalcolmV8]

I had braking problems for a long time that was eventually cured by flushing the brake lines. Long story short my problem was the rear tires always locking up before the front under hard braking. Very annoying and dangerous.

I purchased one of those harbor freight $10 venture vacuum pumps. Got an old glass jar with a metal lid, punched two holes in the lid and put barbed fittings. The jar will catch the fluid instead of it been sucked into the vacuum pump.
I hook it up to a wheel, crack the bleeder and the pump sucks like hell and then I just keep adding fresh fluid to the master cylinder until the fluid running into the jar turns clear.

They say brake fluid attracts moisture and should be flushed every so often. I forget the exact recommendation but I now do mine every 2 or 3 years.

 

[Glacier991]

I built the pressure bleeder as shown in the Explorer Maintenance page. It works great.... though I wish the garden sprayer trigger had a lock position. I think I posted pics of it somewhere on here. Total cost was under $20.

Here are some pics:

and finally the piece that makes it all work... screws onto the master cylinder reservoir

[EDIT: I decided it wouldn't be complete without a pic with fingers in it]

 

[LukeDog3D]

hahahaha, nice

 

[Rhett]

Do you flush your brake fluid? How often? What technique? Why do you flush the brake fluid?

Thanks ......

I have bled the brakes at the caliper/drum, but never at the hydraulic control unit on this truck. Why? I fear getting air into the system and causing a spongy pedal problem and weird ABS issues.

I probably could do a complete flush, including bleeding the HCU, but I have never gotten up the nerve. I know it probably needs it. It's not like the 1st gen ABS is worth anything anyway. If the pedal gets spongy after bleeding I guess I would have to take it to a dealer and have them hook up the ABS unit to their machine. I just don't like having other mechanics touch my truck.

I'm not very good a bleeding brakes, and I feel like the 1-man bleeder I have is not very effective. I should build one of those bleeders like Glacier991 posted about, above. It looks very nice.

 

[Brock94]

I probably could do a complete flush, including bleeding the HCU, but I have never gotten up the nerve. I know it probably needs it. It's not like the 1st gen ABS is worth anything anyway. If the pedal gets spongy after bleeding I guess I would have to take it to a dealer and have them hook up the ABS unit to their machine. I just don't like having other mechanics touch my truck.

If you use the turkey baster to remove the old fluid from the reservior, then bleed at each brake cylinder/caliper until the fluid runs clear (refilling the reservior when it get low), then the whole system is bled-- including the master cylinder and HCU. You just have to be extra careful not to let the master cylinder run dry so that air gets in the system above the HCU. The only way to bleed air out of the HCU is if you have a scan tool that can activate the brake solinoids and allow the air to bleed out.

 

[Rhett]

If you use the turkey baster to remove the old fluid from the reservior, then bleed at each brake cylinder/caliper until the fluid runs clear (refilling the reservior when it get low), then the whole system is bled-- including the master cylinder and HCU. You just have to be extra careful not to let the master cylinder run dry so that air gets in the system above the HCU. The only way to bleed air out of the HCU is if you have a scan tool that can activate the brake solinoids and allow the air to bleed out.

Good point. I have turkey-basted out the master cyl. in the past, in conjunction with bleeding at all 4 corners--but I did not realize/think I had gotten it all out.

 

[MONMIX]

I just did mine a few weeks ago.
Fifteen mineuts with a helper.
1 bottle of Valvoline Synth brake fluid.

FYI, you dont need to PUMP the brake. Just pressure with your foot. Open the bleeder, foot hits the floor, close the bleeder, pressure on the pedal, repeat.

Cake job, with a noticable differance.

 

[Glacier991]

I will admit, I am a believer in a turkey baster in your tool box. I always try and remove old fluid from the reservoir and have it full of clean new fluid before I start... why be pumping old fluid through the system?...

 

[MONMIX]

The " problem " with the turkey baster for brake fluid is the fact that there really is not a lot of "flow" in there. I recon not as through of a result may come.

A helper, some jack stands, a 3/8 wrench, fifteen mineuts. That is tough to beat.

 

[Glacier991]

Hmmm maybe I am not doing a good job explaining this turkey baster thing.... I will swish the fluid around the the reservoir using the baster, then again using the baster empty the reservior, add new fluid to the top and hook up the pressure bleeder, already pumped up. I use a piece of wire to hold down the trigger and then go to the far point and bleed until it runs clear, then the next most, etc, until I am done. Sometimes I may have to repump it once or so. A helper would be nice.....

 

[Rhett]

Hmmm maybe I am not doing a good job explaining this turkey baster thing.... I will swish the fluid around the the reservoir using the baster, then again using the baster empty the reservior, add new fluid to the top and hook up the pressure bleeder, already pumped up. I use a piece of wire to hold down the trigger and then go to the far point and bleed until it runs clear, then the next most, etc, until I am done. Sometimes I may have to repump it once or so. A helper would be nice.....

I am going to build one of those bleeders this weekend. The only concern I have is finding a cap for the master cylinder. I guess I can find one in a junkyard... Seems like the instructions tell where to find that..

 

[410Fortune]

thats awesome!
Good inovation guys.

I have seen these also made to use the air pressure in the tire to force bleed the system

I seem to need a new caliper or something about every 2 years, or need to remove the rear end or something, so my trucks brake system gets bled the old fashioned way, one wheel at a time, two people method often enough to keep my fluid clean.

 

[Glacier991]

I found my cap the the "Help!" section at Kragen or Autozone, I forget which.

 

[MONMIX]

Hmmm maybe I am not doing a good job explaining this turkey baster thing.... I will swish the fluid around the the reservoir using the baster, then again using the baster empty the reservior, add new fluid to the top and hook up the pressure bleeder, already pumped up. I use a piece of wire to hold down the trigger and then go to the far point and bleed until it runs clear, then the next most, etc, until I am done. Sometimes I may have to repump it once or so. A helper would be nice.....

Yeah thanks for the clarity.
I wasnt even close