Hard pedal...water in the lines

[Kurt64]

Hi everyone...I just bought a t-bucket a few weeks ago and I'm trying to diagnose all of it's issues . The first problem was a hard brake pedal with very little stopping power. I replaced the master cylinder and a section of rear brake line. When I disconnected the the residual valve it appeared that a water was flowing out of the line. Aside from the obvious...flushing out the system with fresh fluid...is there anything else I should do?

 

[HenrysT]

Well you said you bought a new master cylinder, replace everything else all the way to wheel cylinders/calipers! Who knows how long the water has been sitting in there, and I'm not going to tell you that a flush will fix it, you'll be driving down the road when your calipers seize or drums lock up, and it might not be on a nice warm night or in the good part of town.

 

[2old2fast]

Well you said you bought a new master cylinder, replace everything else all the way to wheel cylinders/calipers! Who knows how long the water has been sitting in there, and I'm not going to tell you that a flush will fix it, you'll be driving down the road when your calipers seize or drums lock up, and it might not be on a nice warm night or in the good part of town.

Good Lord , you sound like an insurance man ....flush it & drive it , if things were gonna seize they'd have done it while sitting , flush well ., Drive.. BTW. EVERYTHING FAILS..

 

[HenrysT]

I would like to say just flush it, but dealing with people,they will try to hold you to your word when things go wary. Maybe some of the wheel cylinders are already frozen, thus the hard pedal.

 

[2old2fast]

If "they" are not sharp enough to check the whole system , they should not be working on vehicles !

 

[fletcherson]

What does the fluid coming out of the wheel cylinders and calipers look like? Is it clean or real nasty, or does it have water? Make sure that the wheel cylinders and calipers are actually working. If it were mine, I would likely disassemble each wheels brake assembly and inspect to determine that they are all ok. I would be highly suspect of that residual valve or anything else that had moisture in it. Chances are, the residual valve blocked and retained the moisture, but it’s the brakes and there isn’t much between the driver and other items like trees, cars, houses, etc in these things... some sarcasm implied, just be safe.

 

[GreggDaniels]

Brake wheel cylinders and brake lines are cheap to replace. Personally, I would just change them all out and have the secure feeling that they are good to go. The front and rear axles in my car came out of a '66 chevy g10 van and even though I drove the van for four years with no problems I made sure everything associated with the brakes was brand new. If you step on the gas and nothing happens no big deal, if you step on the brakes and nothing happens dirty laundry will be the least of your worries.

 

[Kurt64]

I changed all of the rigid line for new but flushed the flexable braided lines to save them. There definately was water in the system and the old fluid was dirty. I installed a new 1" bore mc, proportion valve (one line in and one out for rear only), and replaced the residual valves front and back. Everything is working well now...still fine tuning the valve to balance the front/back braking power. Now all I have to do is figure out what is causing the pads in the front to squeal. Thanks for the advice everyone.

 

[old round fart]

Disk squeal means brakes may be dragging. I don’t think disk brakes need residual valves do they?

 

[AusBucket]

G'Day Kurt,
After what you have posted in this thread, I can't emphasise enough (for your and your passengers safety) the need to dismantle the callipers and the wheel cylinders and clean them out properly. If the lines had water in them then the callipers and wheel cylinders had water in them as well. Hoses are cheap as are all the rubber components. If you do the lot now you won't be suffering "failures" down the track. I've been building cars from scratch for 20 odd years and we never put a car on the road without renewing the brake system. Not trying to teach you to suck eggs, just a bit concerned when I read what's posted.
Regards,

 

[HenrysT]

Disk squeal means brakes may be dragging. I don’t think disk brakes need residual valves do they?

You use residual valves when the M/C is LOWER than the calipers/ wheel cylinders to prevent the brake fluid from draining back to the M/C. and since the disc brake system "uses" more fluid,they would definitely need the valve to control the fluid. If the M/C is mounted on the fire wall, you probably wouldn't need the valves.

Are the calipers moving/sliding freely? NOT JUST THE PISTONS but are they moving on their pins/slides? Did you replace them? It could be the make-up/compound of the pads, are they ceramic? organic? What kind of brakes are you running? GM, Wilwood?

 

[2old2fast]

Residual valves are not needed , think about it , brakes are a closed hydraulic system , in order for fluid to flow towards the MC there would have to be reverse pressure in the system or air entering at the caliper/ wheel cylinders , and/or air escaping (being displaced) at the MC in order for fluid to move in that direction....please , think it over , the MC is sealed , the lines are sealed , the wheel cylinders. / Calipers are sealed. It's my opinion that residual valves are marketing hype....

 

[T-Test]

Bend/tighten the tabs on the brake pads to hold them tight on the calipers. I do this and then squeeze them onto the calipers with channel lock pliers. Them being loose is usually the cause of squeal or the pads have hardened and glazed over. You can sand them, but is better to replace.

Water in brake system is never good. Clean all including calipers and cylinders and you can run some water drier through the lines or replace. Water causes brake fade as it has a lower boiling point than brake fluid.

Don't be afraid to ask for help from another gear head as I don't want to see any unsafe Bucket on the road. There is enough IDIOTS already out there.

 

[2old2fast]

Disk squeal means brakes may be dragging. I don’t think disk brakes need residual valves do they?

All disc brakes drag , they're supposed to . Drag is also what causes the squeal , but it's usually controlled by the backing on the pads or clips . Some brake pads are sold with a packet of gel that you apply to the back of the pads to suppress the squeal.

 

[HenrysT]

It is a closed system, yes, BUT both ends are aloud to move (expand and contract). I'm not saying that the fluid will drain back instantly or even in a few seconds or minutes, but it will drain back. If you have to store it over the winter, you will have to "pump up" the brakes come spring time. Do what you want, just don't ride behind me. Try it with out it, but if you notice the pedal feeling spongy ...

JMHO

 

[2old2fast]

The only "force" that would cause fluid to return to the reservoir is gravity ,no?. You're saying there's enough gravitational force in the 3"or4" drop from the wheel cylinders to force air ( remember , you must allow air in so that fluid can move ) back to the MC in sufficient quantity to affect brake performance???

 

[HenrysT]

Gravity yes, air no. Have you ever done a brake job and collapsed the calipers to install the new pads? Did air enter the system? Did you pump the brakes to bring the calipers back in contact with the rotors? Calipers move in and out and the diaphragm in the MC moves in and out.

 

[old round fart]

Think I’ll leave out the valves on mine.

 

[409T]

Residual valves are not needed , think about it , brakes are a closed hydraulic system , in order for fluid to flow towards the MC there would have to be reverse pressure in the system or air entering at the caliper/ wheel cylinders , and/or air escaping (being displaced) at the MC in order for fluid to move in that direction....please , think it over , the MC is sealed , the lines are sealed , the wheel cylinders. / Calipers are sealed. It's my opinion that residual valves are marketing hype....

YES!

 

[2old2fast]

Gravity yes, air no. Have you ever done a brake job and collapsed the calipers to install the new pads? Did air enter the system? Did you pump the brakes to bring the calipers back in contact with the rotors? Calipers move in and out and the diaphragm in the MC moves in and out.

You have to apply a significant amount of force (c-clamp) to collapse the caliper and if you don't take the MC cover loose you push fluid out past the lid seal , that ain't happening driving down the road or sitting parked.