Brake Trouble

Jigg · Post by **Jigg** » Thu Jun 15, 2006 5:16 pm

Recently, my brakes have been kind of f-d up. One of the pads in the rear somehow dislodged itself and completely ground down the rotor on that side. I replaced pads and rotors in the rear. Now, every once in awhile (maybe once every 80 miles), my brakes have a ton of resistance in them. It's almost like the ABS is kicking in, but if i press harder on the pedal, it goes back to normal. Think i toasted my brake fluid when the other rotor got all messed up? Can we add synthetic fluid to the stock fluid?

F9K9 · Post by **F9K9** » Thu Jun 15, 2006 5:42 pm

A lot of good info on this topic when "KILLIAN" (STEVE) and HJ reads your question. Sorry, if I am of no assistance

Post by **HenryJ** » Thu Jun 15, 2006 5:53 pm

To quote another member..."Check your caliper slide pins, and lubricate them".

Wear to one side indicates a stuck slide. Fix that.

I don't like mixing fluids. You may need to change the fluid though. Brake fluid is hygroscopic. It seeks and absorbs water. It does need to be changed. I will admit I fall short in this respect too. When I do a brake job I suck out as much brake fluid from the reservoir as possible. Then compress all the calipers and get all that I can sucked out again. Then fill the reservoir with new fluid from a sealed container. Why sealed? It absorbs water from the air. If it has been exposed to air it has absorbed water.

What does the water do? It lowers the boiling point of brake fluid. It compresses more. This is why you get that spongy feel. It also corrodes the internal components.
DOT 3 and 4 fluids are good in that they do absorb water. The more they absorb the less that can puddle in the wheel cylinders , master cylinder and calipers. That is where the rust and pitting come from.

DOT 5 fluid is silicone and does not absorb water. Those systems must be flushed periodically to remove contamination. It stays firm , but the components seem to suffer when neglected. Systems that are compatible with silicone use special seals. The other fluids are not interchangeable or compatible with a silicone fluid system. The Military used to use silicone sysetms. Some racing uses it and street rods do ocasionally since it is paint friendly.

I am not familiar with the specific properties of the synthetic fluids , but I would say that look for one that is comparable to the affinity for water that DOT 3 has. If you maintain a regular replacement regiment, or endure high heat braking regularly DOT 4 would be my next choice. DOT 4 is less hygroscopic, therefore is not as long lived as DOT 3.

More than you wanted to know probably

never as a simple question, I may go on...and on

Jigg · Post by **Jigg** » Thu Jun 15, 2006 6:04 pm

that's an awesome reply. Thanks man.

I fixed the sticking slides when i did the brakes, so that's all set.

I read another one of your posts about brake fluid being hygroscopic and i went to autozone tryign to find fluid that said it was hygroscopic... needless to say, i left empty handed.

Sounds like the best thing to do would be to get some DOT 3 fluid and change as much of the fluid as possible.

Do you think that the fluid could cause the funky braking?

Post by **HenryJ** » Thu Jun 15, 2006 6:30 pm

Jigg wrote:... i went to autozone tryign to find fluid that said it was hygroscopic...

It will not say the percentage or that it is. That is in the Depertment Of Transportation specification , ie. DOT 3 specifiction. You can reserach DOT specifications to see the properties required to meet this spec.

Sounds like the best thing to do would be to get some DOT 3 fluid and change as much of the fluid as possible.

Yes, can't hurt.

Do you think that the fluid could cause the funky braking?

Not really. It sounds more like a master cylinder, brake booster or other mechanical problem. It is one of those thing you kind of need to be there to diagnose though, sorry.

killian96ss · Post by **killian96ss** » Thu Jun 15, 2006 7:47 pm

I will keep this simple!

This is what you want!

Valvoline synthetic DOT 3 & 4 brake fluid

I use this stuff in all my vehicles, and it's far better than the regular DOT 3 and 4 fluids. If you do use this stuff or any other synthetic brake fluid, it is a good idea to flush the entire system thoroughly with the new fluid.

This is the best stuff you can get without paying high prices for the racing stuff.

For just a little more money, ATE super blue or type 200 is probably the best brake fluid currently available.

Either brand will definitely improve pedal feel and braking performance.

Steve

Jigg · Post by **Jigg** » Thu Jun 22, 2006 4:44 pm

Short of flushing my system, i decided to try siphoning some out and replacing it. The fluid i took out was very dark in color, while the fluid that came out of the bottle was almost clear. Is that normal for it to be two completely different colors?

Post by **HenryJ** » Thu Jun 22, 2006 4:45 pm

It all starts out clear.

Jigg · Post by **Jigg** » Thu Jun 22, 2006 4:54 pm

I just poured some out onto a paper plate (the old stuff), it was like a dark yellow, which i can see being clear at one point. I got a little freaked, 'cus i thought maybe it was synthetic and i just poured in regular.

I just took it for a drive, braking is noticably better, i think i might do it one more time in like a week or so, can't hurt. My brakes feel WAY less spongey than they did before.

Another thing i noticed (don't you guys love having me on here? lol), i get way more brake dust on my driver's side than my passengers side... figment of my imagination or completely possible?

F9K9 · Post by **F9K9** » Thu Jun 22, 2006 5:05 pm

Jigg wrote:...........................Another thing i noticed (don't you guys love having me on here? lol), i get way more brake dust on my driver's side than my passengers side... figment of my imagination or completely possible?

We just want you to "feel welcome" here. I am just speaking for myself but, I'd be surprised if most members do not feel the same way. You have a lot of knowledge to offer and hopefully we do too.

Jigg · Post by **Jigg** » Thu Jun 22, 2006 5:08 pm

I definitely feel welcomed on here. You guys have so much technical knowledge it's unreal. That Tow/Haul thread makes my head hurt it's so in depth. I still can't believe i hadn't signed up here until recently. I'm going to go search and see if i registered under another username or something.

killian96ss · Post by **killian96ss** » Thu Jun 22, 2006 5:24 pm

Jigg wrote:Another thing i noticed (don't you guys love having me on here? lol), i get way more brake dust on my driver's side than my passengers side... figment of my imagination or completely possible?

I can think of 3 possibilities. You might have air in the brakes lines or in the caliper on the side with less dust. Maybe you have sticking or frozen caliper slide pins on one of the calipers. Another possibility is that one of the pistons may have a damaged bore causing it drag harder than the other side or even create a side loading or sticking condition. A worn piston bore is hard to confirm without taking the caliper apart, however the other 2 possibilities can be checked by thoroughly bleeding the brakes and lubing the slide pins.

BTW, I'm sure you already know this, but replacing the fluid in the master cylinder is not considered a flush of any sort and it won't do much good. You need to completely flush the system to get really good results.

Steve

Post by **HenryJ** » Thu Jun 22, 2006 6:17 pm

Try attaching a hose to the bleeder on the farthest wheel open it and let it drain into a container. You can just let it drain if you are working on your own. It will take a very long time. Once that one clears up move to the next. RR, LR, RF, LF.

If you have a friend they can help you bleed the system. Have them apply pedal pressure, then you crack loose the bleeder. Close it when the pedal hits the floor or just before.
Re check the fluid level after a few cycles. Do this until the fluid clears up.
Repeat the process for the next closest wheel and work your way to the wheel closest to the master cylinder.

I hate to say it, but if the fluid is that bad , failure of your master cylinder may not be far behind.

Jigg · Post by **Jigg** » Thu Jun 22, 2006 7:00 pm

Who was it that i saw post about removing brake fluid with a turkey baster and replacing it to freshen up the system? That's what i was trying to accomplish. edit: nevermind, i found the post i was referring to... guess i forgot the part about compressing the brakes to get all the fluid out

The fluid was like an amber color, it wasn't muddy or anything, just, in comparison to the nearly clear new stuff, it had way more color...

Thanks for all of the help guys... i'm hoping that everything is ok, i'm just new to working on the brake system.

Post by **HenryJ** » Thu Jun 22, 2006 7:19 pm

Once you get things "cleared up", just plan on replacing what you can from the reservoir when you do the brakes.
You are right. Any amount you can replace will help. It is the water that it has acquired as well as other contaminants you are removing.
It is kind of the same situation that exists for the cooling system. If you drain the radiator and add fresh, it does help, but the stuff left in the block dilutes it. The same can be said for a transmission service. The pan only holds five quarts. Over half the capacity remains unchanged with out a fluid exchange.

That is kind of what is happening here. I do not know the system capacity, or how much is in the system beyond the reservoir. It is worth your time to go ahead and complete the job though. Just changing the reservoir again will not do much since the fluid does not cycle through.

You have done some good. You can do more if you wish.