Help! Four mechanics are stumped.
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Junior Member
Joined: Dec 2006
Posts: 8
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Dudes, I'm listening. I've answered many of the questions. I just don't know if it has a limited slip.
Man you guys are tough. I work seven 12hr shifts at a hospital. Don't get to look at this as much as I'd like(hell with him? WTF).
Anyway, dealer called yesterday, still working on it. They are looking closer at the brakes.
Man you guys are tough. I work seven 12hr shifts at a hospital. Don't get to look at this as much as I'd like(hell with him? WTF).
Anyway, dealer called yesterday, still working on it. They are looking closer at the brakes.
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Joined: Apr 2008
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Glad I read this thread. Have had a similar problem for 12 months or so on a '98 4.6L. Mine was definitely a caliper sticking, but at the time it started there was a noticeable smell (smelled electrical to me), already had the cruise control recall fix done, so I wasn't too worried about a fire (kept it parked away from the house anyway), and no noticeable other problems---so I figured the problem would identify itself further in time. When the squealer on the pads started making noise (at about the normal expected time) I changed them and discovered noticeably more wear on the driver's side than the passenger's. Changed the pads and within 4 months went from bad to worse. The caliper was definitely sticking (truck pulling to one side and rpm's too high to maintain speed)---but only some of the time. Seemed to be much worse when the engine was hot and even when the outside ambient temp was warmer (even remarked to a buddy at work that they never stuck at 5:00 in the morning on the way to work, but at 4:30-5:00 in the afternoon, you could almost count on it). Replaced the caliper and pads again (had the lifetime warranty pads, boy did they get sick of seeing me---sometimes it feels good to stick it to the man). Figured problem solved. No dice---within the last two months it started again (and I've changed the pads again). If you're noticing that type of smell, I'd be highly suspicious of the front brakes. Hard to believe experienced mechanics wouldn't be able to identify the problem, but neither did I. Like I said, there were no noticeable problems associated with it at first---it seems to get progressively worse over time. Anyway, I was planning on flushing that whole brake line this week, but I never suspected the master cylinder. Is it possible that it would bind just one caliper and not the other, or the rear brake drums? The driver's side front is the closest to the MC. Not sure if the modern trucks still use a differential valve, but if memory serves, on the old F150's the valve only separated pressure from back to front---not side to side. The pistons in that one caliper are impossible to force back without loosening the bleeder (on the old one and the new one)--and there's only rear-wheel ABS, so I'm guessing that's not part of the problem. If you take a long drive-at least 20 miles- and it seems like you're having that problem, as soon as you stop stick your nose down around the front wheels and see if there isn't a noticeable difference between the two. Sorry for the long post---food for thought. The Vinman
Senior Member
Joined: Mar 2001
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From: Seabrook,NH
You'll never fix it....I replace every part in the brake system at least twice including the master cly. The brakes still overheat, drag, stick, fry brake pads, pull, and generally suck. They also heat up the front rims so much I've almost lost the truck to fire a couple times. I've worked on them, a private shop and the overpriced dealer also. NO ONE CAN FIX IT. If you think you did fix it, it will be back in 50-10,000 miles. Ford quality.........Sorry for the bad news.
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
There is a little knowledge to it - sampson01 nailed one of them that people tend to neglect = Brake hoses. They DO break down with time. They collapse and restrict flow to our twin piston systems. Flow and CLEAN fluid is key, without that you'll have all sorts of problems with these systems, specially up front.
Senior Member
Joined: Jan 2008
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From: Boston, Ma
ive seen it all the time .... chevy 1500s f150s cars trucks suvs everything .... one main problem is when techs go to do calipers they use hose crimpers or visegrips on the hoses to stop the flow of brake fluid out of the line.... problem is that could be pinching the inner liner of the hose thus breaking down the materials that make up that hose .... higher brake fluid temps cause worse braking causing more heat= glazing of pads.. bluing of rotors warped rotors and broken down brake hoses .... hopefully that helps ya out
also have to looked at the check valve on the booster ? thats goes into the booster connected to the hose running to the intake
also have to looked at the check valve on the booster ? thats goes into the booster connected to the hose running to the intake
I would have to drive it. Its hard to say over the internet without feeling the grabbing you describe or smell what you smell. Almost sounds like to me the Cats are plugged. The bucking would be the engine sufficating and the smell is the exhaust being forced out the wrong way.
A truck cant eat more air if it cant poop out its meal. I would think your cats are clogged to the point that it takes time for enough exhaust to fill the system as opposed to clogged enough to make the truck undriveable.
Take out the rear 02 sensors and check that way. Personally being a mechanic I can say just because a guy is a mechanic, in no way in hell does that make him a "professional". Oh and exhaust being plugged up would not cause an Check Engine Light in most cases from what I have experienced.
A truck cant eat more air if it cant poop out its meal. I would think your cats are clogged to the point that it takes time for enough exhaust to fill the system as opposed to clogged enough to make the truck undriveable.
Take out the rear 02 sensors and check that way. Personally being a mechanic I can say just because a guy is a mechanic, in no way in hell does that make him a "professional". Oh and exhaust being plugged up would not cause an Check Engine Light in most cases from what I have experienced.
Last edited by IR0NS1N; Sep 3, 2009 at 08:49 PM.
No a plugged cat doesnt mean its 100 blocked off, it can take time for the effects of the partial blocked cat to take notice. after you drive for a while if all the exhaust cannot escape it will create alot of back pressure eventually not allowing anymore exhaust out of the cylinder heads. Usually I see cats that are clogging and the main complaint is after a while going say 50MPH the car is gutless. Or it wont reach a certain speed.
I do mean pull the first O2 sensors out before the cats, or even disconnect the downpipes after the exhaust manifolds.
I do mean pull the first O2 sensors out before the cats, or even disconnect the downpipes after the exhaust manifolds.
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Right lol. Just having fun with Whiteghost a bit.
No offense, but it sounds more like HE is the one that hasn't figure it out. Techs, Mechanics know this stuff, but yea this thread was pretty much toast. So my posts weren't intended for the OP, since he hasn't been around in awhile.
You would be surprised how many replace the rotors, pads, calipers - just about everything before they get to the rubber hoses lol., - Those hoses are more delicate than one would think. I run braided now, but I've read thru the installation instructions on rubber sets. It will say something like ~ Hang them @ room temp for a period of time before installing - it's a good stretch , like 8 hours...I guess that's because their somewhat bound in it's packaging.
But yea, I've seen em abused many times
No offense, but it sounds more like HE is the one that hasn't figure it out. Techs, Mechanics know this stuff, but yea this thread was pretty much toast. So my posts weren't intended for the OP, since he hasn't been around in awhile.You would be surprised how many replace the rotors, pads, calipers - just about everything before they get to the rubber hoses lol., - Those hoses are more delicate than one would think. I run braided now, but I've read thru the installation instructions on rubber sets. It will say something like ~ Hang them @ room temp for a period of time before installing - it's a good stretch , like 8 hours...I guess that's because their somewhat bound in it's packaging.
But yea, I've seen em abused many times
Last edited by jbrew; Sep 3, 2009 at 10:36 PM.
Senior Member
Joined: Nov 2006
Posts: 2,068
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From: So. Cal.
You would be surprised how many replace the rotors, pads, calipers - just about everything before they get to the rubber hoses lol., - Those hoses are more delicate than one would think. I run braided now, but I've read thru the installation instructions on rubber sets. It will say something like ~ Hang them @ room temp for a period of time before installing - it's a good stretch , like 8 hours...I guess that's because their somewhat bound in it's packaging.
But yea, I've seen em abused many times
But yea, I've seen em abused many times
