Question for Allan In NE

RCP · Jan 2, 2013

Allan

Looking for some help with my 2005 Chevy 2500 HD, with a 6 litre gas and manual transmission. Over time the brakes have become less effective. It has good rotors and pads (aftermarket)and I have replaced the ABS sensors in the front hubs. The brake fluid has turned dark brown and the area around the master cylinder and hydrobooster is wet, but I do not see the source of a leak. The pedal feels ok, not mushy but probably not as solid as when the truck was new.
I have been looking at variuos forums, and it has been suggested to flush the brakes. But no idea on the wet area.

Looking forward to suggestions.

Thanks
Rich

Janicholson · Jan 2, 2013

Were it mine I would sure flush the system first. I like to use synthetic brake fluid if allowed by the MFG. It seems more stable and absorbs less water. Start with the farthest away bleeder and progress to the closest one. Push gently on the pedal, or use a power bleeder. so as to not displace the system warning light. If you changed the pads, a harder (more metallic) compound will take more foot pressure to stop. If the pedal is spongy, look for sticking caliper mounts, If the brakes pull, or have differences in pad wear, look for stuck caliper pistons. Jim

RCP · Jan 2, 2013

Thanks for the feedback

Rich

Duner Wi · Jan 2, 2013

Don't confuse synthetic brake fluid with silicone
DOT 5 like some people do. DOT 5 requires a through system flush with alcohol as I understand it.

RCP · Jan 4, 2013

Thanks

RCP · Jan 4, 2013

Thanks

Owen Aaland · Jan 5, 2013

(quoted from post at 20:55:24 01/02/13) Were it mine I would sure flush the system first. I like to use synthetic brake fluid if allowed by the MFG. It seems more stable and absorbs less water. Start with the farthest away bleeder and progress to the closest one. Push gently on the pedal, or use a power bleeder. so as to not displace the system warning light. If you changed the pads, a harder (more metallic) compound will take more foot pressure to stop. If the pedal is spongy, look for sticking caliper mounts, If the brakes pull, or have differences in pad wear, look for stuck caliper pistons. Jim

The problem with DOT 5 synthetic fluid is that it DOESN"T absorb moisture! It does have a higher boiling point than DOT 3 or DOT 4 fluid but water will still condense in the system. Since the fluid does not absorb the moisture and hold it in suspension it collects in the lowest parts of the system. The wheel cylinders are the most likely place where this water collects and as a result rusting and destruction of the cylinders is a bigger problem than using DOT 3 or DOT 4 fluid. Since the bleed screws by necessity have to be on the high points of a system to be able to bleed the air from the system, the fact that any water has collected in the low areas of the system means that this water can not be bled out like it can in systems where the water is held in suspension.

Question for Allan In NE

RCP

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Janicholson

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RCP

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Duner Wi

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RCP

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RCP

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Owen Aaland

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