THSCC Forums

Maybe this should be a poll - but there's been enough of those lately

I'm helping a friend with her 97 Chevy truck - the brakes feel *terrible* to me - spongy, overboosted, and you can push the pedal right down to the floor after stopping with enough effort.

Some googling leads me to plenty of threads about 'that's just the way these Chevy brakes are' - even an article from a parts supplier to service reps about how to deal mainly with the customers, not the brakes!

I'm going to probably have a go at a full system flush, and see if I can get the device needed to actuate the abs during bleeding.

How many Chevy truck owners here have this problem, have solved it, or are just living with it?

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

I have a 99 with abs. I would not say the breaks are spongy or weak in the least. They slow me Down quick enough to warp the roaters while running through deals gap.

Define "enough effort". Is that enough effort to engage the ABS on dry pavement? Might just be the product of a small diameter MC and maximum vacuum available at idle.

If you turn the engine off and pump the pedal to use up the residual vacuum in the booster, is the pedal still squishy?

(As a last resort, consider retrofitting the truck with Fox-body Mustang brakes )

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Art McDonald
Premier Amateur #518
2008 Dishman Cup
Pivot Cone Snob

Rodney is a waxer (but in a good way)

If everything at the wheels checks out good, and there is no air in the lines, then I think it's got to be the master cyl or proportioning valve.

I don't understand how the proportioning valve can cause this, but I had it happen in 2 GM RWD vehicles when I was younger. Each time, the shop did the master cyl first, that didn't fix it, so replaced the prop valve, and that fixed it.

Or can the ABS itself cause this?

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91 RallyX Audi Coupe Quattro
89 A-Team Astro-van demo derby winner at 2011 NC State Fair (http://www.youtube.com/watch?v=7MrZqwENRqU)
Broken 89 Subaru GL-10 RallyX turbo wagon - need to sell it and all my parts cars

My 01's brakes are likely similar, and I too have done the Interweb searching. Chevy has gotten a lot of comments on this, and they addressed it (supposedly) with the latest body style by increase stiffness of the firewall and MC/booster and going back to rear drums (maybe that was just cost savings, too).

They have a lot of pedal travel before they start to hook up, but after an inch or two they start to grab decently. Now, if your pedal is truly going to the floor, then you may have an issue - but an inch or two of pedal travel before anything good happens is pretty normal. If you reference is your Ford truck, then I see the issue - Fords have a COMPLETELY different brake feel that is much more reassuring.

FWIW, my concerns for my truck's brakes went away when I got my M3 and realized those are just as bad. You get used to it.

Note that corrosion on the rear calipers is common on these as well since the rear calipers are more exposed than in cars (due to lack of rear wheel wells). These trucks are are also heavily rear brake biased (as in I have 120k miles on my ORIGINAL OEM front pads, though the rears were changed at ~80k). Put these 2 issues together, and you have a system biased toward the end that doesn't want to work right. Consider at least a careful inspection of all the moving parts in the caliper and whether a rebuild/replacement might be in order.

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Dustin Fredrickson
-- I'm a nobody --

Interesting. My sister has a late 90's Suburban and the brakes suck in the same manner. Every time I drive it, the first stop literally scares me. Two (or more) inches of travel before you feel anything does not inspire confidence. My reference is my Z-24, which has less than 2" of travel from nothing to rock hard. The stock brakes had a little more travel than the ZR-1 conversion, but not much more.

With this info it sounds like I can chalk it up to "it just does that", which sucks, but at least it's not mine.

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Vincent Keene
'06 Ford Mustang GT (track rat)
'15 Dodge Charger R/T (yeah, it's got a HEMI!)
'07 Ford Fusion SE (205,000 miles and counting)
'98 Chevy Z-24 (retired)
'93 Acura Integra (Team SWB 24HOL Car)

Thanks for all the input - I'll post an update if I figure anything out.

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!