Changing or not changing brake fluid

[Robert B.]

Re: Changing or not changing brake fluid

I change my fluid by drawing it through the calipers with a vacuum bleeder. I draw fluid until I see clean fresh fluid flowing.

[Phil D.]

Re: Changing or not changing brake fluid

I was told by one person that some dealerships do not flush the brake system but just suck out the fluid from the master cylinder and add new fluid.Would that suppose method do any good with the old fluid still in the calipers? That is how many mechanics do transmission services. The drain the pan add a new filter and the rest of the fluid stays in the converter.

Unlike those other systems, brake fluid doesn't readily circulate from the calipers back to the master cylinder so the idea of just adding fresh fluid doesn't help much if any at all. Luckily we can buy reproduction, rebuilt or at least suitable replacement parts for Corvettes but I've restored much rarer cars for which parts are not available. The only solution is to send parts off to someplace like Whitepost to be bored out and sleeved at considerable expense or adapt a non-original part. I've gone searching salvage yards and opened up many brake master cylinders only to find they're not useable because I think 95 out of 100 car owners never change their brake fluid unless or until the brakes need repair. Most people seem to know they're supposed to get the oil changed even if they don't do it on schedule, but I think very few people nowadays are educated about the other fluids in a car. As to fine European cars specifying frequent changes, I can't speak to all, but I happen to own a 2000 Jaguar. The owners manual specifies almost no maintenance all and the chart stops at 100K miles. I don't know if they figured the car would never make it to 100K regardless how well it was maintained or if the marketing department overruled the engineers and just lied about how little maintenance was required. In the modern age, low maintenance is a big selling point for new cars and I think the manufacturers don't care anything about the second and third owners. As long as the original owner doesn't have any problems with a car, he'll come back and buy another one and that usually happens well within the lifespan of every fluid except the engine oil.

[Pat H.]

Re: Changing or not changing brake fluid

I had a brake fluid flush done in my 06 in the spring of 2013. I noticed early on this driving season that its just a murky as when I brought it in to the dealer. I driven the car approx. 5000 mi since the work was done. I don't think it was done properly or as Walter suggested they just suck out whats in the master. My BMW was done in 2012 and its still pretty clean. I'll ask the next time I'm at the dealer how they do it. I was not impressed.

[Terry M.]

Re: Changing or not changing brake fluid

I had a brake fluid flush done in my 06 in the spring of 2013. I noticed early on this driving season that its just a murky as when I brought it in to the dealer. I driven the car approx. 5000 mi since the work was done. I don't think it was done properly or as Walter suggested they just suck out whats in the master. My BMW was done in 2012 and its still pretty clean. I'll ask the next time I'm at the dealer how they do it. I was not impressed.

Pat,
Your suspicions are one of the many reasons I do my own work where ever possible, and this is one area where it is not only possible, but preferable.

[Michael F.]

Re: Changing or not changing brake fluid

on my older cars i use gravity bleed on all wheels every few years, takes a while but works great and easy for one person to do.

[Donald A.]

Re: Changing or not changing brake fluid

on my older cars i use gravity bleed on all wheels every few years, takes a while but works great and easy for one person to do.

Can you explain the procedure for gravity feed you do

[Wes S.]

Re: Changing or not changing brake fluid

I've always used Castrol LMA low moisture absorption brake fluid and drain it every 2 years--gravity bleed. Cheap insurance.

[Michael F.]

Re: Changing or not changing brake fluid

loosen top of master so you can keep eye on level and top off as needed, do one at a time. go to brake caliper nearest master first and then work around to rest with farthest one away last. open bleeder screw and let drain until fluid is clear, will take awhile so keep eye on master level, after fluid clear close bleeder and move on to next brake caliper and repeat until all done.......be sure to keep eye on level of fluid in master and top off so no air gets into system. hope that is clear.

[Leif A.]

Re: Changing or not changing brake fluid

loosen top of master so you can keep eye on level and top off as needed, do one at a time. go to brake caliper nearest master first and then work around to rest with farthest one away last. open bleeder screw and let drain until fluid is clear, will take awhile so keep eye on master level, after fluid clear close bleeder and move on to next brake caliper and repeat until all done.......be sure to keep eye on level of fluid in master and top off so no air gets into system. hope that is clear.

Michael,

Can this method be used if changing from DOT 3 or DOT 4 to DOT 5??

[Joe L.]

Re: Changing or not changing brake fluid

Michael,

Can this method be used if changing from DOT 3 or DOT 4 to DOT 5??

Leif------


No. Using this method would cause the DOT 3 and DOT 5 to "mix". That's the last thing you want. To convert from glycol-based fluid to silicone based, you have to remove all of the old fluid from the system. This pretty much means rebuilding the calipers and master cylinder to clean out all the glycol fluid and thoroughly flushing the brake lines.

[Leif A.]

Re: Changing or not changing brake fluid

Leif------


No. Using this method would cause the DOT 3 and DOT 5 to "mix". That's the last thing you want. To convert from glycol-based fluid to silicone based, you have to remove all of the old fluid from the system. This pretty much means rebuilding the calipers and master cylinder to clean out all the glycol fluid and thoroughly flushing the brake lines.

Thanks, Joe. That is what is surmised and why I asked. I appreciate your response.