Georgia Fiero Club Forum
All Things Fiero => General Fiero Discussion => Topic started by: Raydar on May 24, 2018, 10:25:56 pm
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I have been having an issue with my left front wheel locking up long before the others. I have done all the usual stuff. Checked/replace hoses, calipers, and pads. Bled everything to a fare-thee-well. Etc., etc. I have replaced everything but the master cylinder and proportioning valve.
I was looking for a proportioning valve, when someone suggested that my suspension might be unevenly loaded. If the left front is not holding up its fair share of the weight, it could, theoretically, make the wheel lock up prematurely. (This, in spite of my fat azz being in the driver's seat.)
With that said... I probably should have the car weighed, corner by corner. Lots of race shops are equipped to do this but, unfortunately, I don't know any of them.
Anyone have any suggestions? (I have already heard the suggestion of driving up to the weigh-station scales, when they're closed. Don't really want to try that, just yet.)
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How about the brake hoses? Maybe the right front is starting to collapse and not letting an even amount of pressure go to both front wheels?
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Let me make a phone call and I should have access to a set of scales. We can find corner weights, cross weights, front %, rear %, with without driver, etc
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Hey Scott, I would surely like to get in on that also, I haven't Scaled mine yet and really need to. Season has started AGAIN and I'm still not ready.
Thanks.
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Charlie, the brake hoses, calipers, and pads have been replaced. Thinking about it, the car has been that way, as far back as I can remember. Nothing that I have done, has helped.
I was about to try to find a proportioning valve. It's the next - and last - logical piece to replace. If I have to, I'll steal one off of the "ghost in the machine" (aka "the project".) But I'd rather not.
The master cylinder is really not suspect, since it feeds both fronts out of one port. The proportioning valve splits it up, left to right.
Scott, sounds good. Please let me know what you find out.
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You could convert your Fiero to right drive, to see if the weight change helped. J/k.
Seriously, though, after the scales, you could test brake pressure at the caliper, for each wheel, or at least for the front wheels. I would expect them to be the same, side to side.
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You could convert your Fiero to right drive, to see if ghe weight change helped. J/k.
Seriously, though, after the scales, you could test brake pressure at the caliper, for each wheel, or at least for the front wheels. I would expect them to be the same, side to side.
That's a thought. But, just like the scales, I don't have the tools handy, to measure this.
Fieroguru quoted some really high pressure numbers. Takes better equipment than I've got. But That's probably next, if I don't just "shotgun it", and replace the proportioning valve.
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Well, see what the scales show. Maybe a trip to Champaign, IL is in your future.
Just curious, but how do you do the track stuff and the RFTH events with brakes like this?
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There's a good proportioning valve on the Warrior Project car.
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There's a good proportioning valve on the Warrior Project car.
That's a thought. I'll message Paul, later on. Thank you. :)
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No scales, yet?
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Not yet. Have some leads...
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Still nothing?
This will be available at the 35th.
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Raydar, do the other 3 wheels lock up?
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The other day, I managed to lock up the front right side. So it may just have been road conditions. Not going to worry about it too much, for now.
Car isn't drivable, just now, anyway.
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I will relate 2 experiences that may help.
The first involved a tire rotation. After the tire rotation, my wife's truck pulled hard to the right in the right lane on a stretch of highway on her way home from work. Just for about 1 mile. I duplicated this on a side street, rather by accident. No idea why. We replaced the front tires, and the problem went away.
Yesterday, the brakes went out on my Fiero, due to a leaking left rear brake hose. As I got low on fluid, one of the wheels would lock up, but only after 90% of the pedal travel. Nothing happened until after the last 10%, with the pedal basically on the floor. My situation yesterday reminded me of this issue of yours. At the time, the prevailing thought was that it was a bad left rear caliper. Eventually, I crawled up under the car and found out what was happening. My brake fluid was seriously low, with the rwar chamber basically empty.
I wonder if you could have a flow situation. Maybe rather that test weight at the wheels, check fluid pressure at the calipers. Or, maybe it's a tires issue.
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Based on watching a variety of Fieros being weighed, each corner has a different weight. Unless you had another identical Fiero with which to compare, the weights would have to be weigh (ha, ha) off.
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I did a bunch of brake tests in my '88. Because of how the brake lines/hoses are run, the wheels tend to lock up differently. I have a different setup than you have, but my Fiero locks up differently in different circumstances. Usually the left front locks up first, because it gets the most direct brake pressure; however, other wheels lock up in other circumstances, like going downhill.
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I did a bunch of brake tests in my '88. Because of how the brake lines/hoses are run, the wheels tend to lock up differently. I have a different setup than you have, but my Fiero locks up differently in different circumstances. Usually the left front locks up first, because it gets the most direct brake pressureb however, other wheels lock up in other circumstances, like going downhill.
I think I mentioned, elsewhere, that the left front seemed to be the one that locked. The other day, the right front locked, so maybe it's just a function of the way the car is loaded, and the road surface, as much as anything.
I'm still trying to get the car back together from the motor mount situation, so the brake thing is on the back burner, for a while. Maybe indefinitely, unless I get surprised.
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I did read that post, and did not forget, but I wanted to post my results. I hope that our posts will help others in the future.
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So, all good?
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As far as I know. Haven't really bothered with it, since.
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I have the technology just the distance might scupper us Raydar.
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It's all good. I haven't even thought about it in months. Since I slid the right wheel, instead of the left, on that one occasion, I just decided it was the way the car was loaded.
With that said, ALL 88s tend to have a front bias with the brakes. Normally, that's desirable, but I think the Fiero is "overboard" in that regard.
I thought about going up by one tire size in the front (from 215 to 225) but the person I mentioned it to (fieroguru) didn't seem to think it would be useful, and he's got extensive experience doing stuff like this.
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Ummm...... I not an engineer nor did I stay in a Holiday Inn last night, but I believe ALL cars have a front brake bias. I think it has something to do with physics. I think :-[ that is why front brakes always wear out first
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Ummm...... I not an engineer nor did I stay in a Holiday Inn last night, but I believe ALL cars have a front brake bias. I think it has something to do with physics. I think :-[ that is why front brakes always wear out first
It's by design. Rear wheels locking first can throw the car into a skid. It can be designed out, but it wouldn't be the best idea. I just think the Fiero goes overboard. Hence the occasional "brake proportioning valve" thread you might see on Pennocks.
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The Fiero is too light in the front. Adding a bit of weight helps to alleviate this issue.