You're a good man to try to help everyone! You don't get anything more than recognition as a master technician for doing it. It looks like Dime is doing his part as well!

The P0446 was close to my heart, since I had one on my 2006 G6 a few years ago. Was the first time I dug out the factory shop manuals I bought for it when it was new, and tried to work with an OBDII system. Once you read the descriptions of the code and review the circuits, you can develop/improvise your own diagnostics using a multimeter as Dime said - but you first have to understand exactly what is going on, how things work, and be able to take a leap of faith for the things you cannot check.

BTW, for me it was the solenoid - a cheap fix.

I used to be a dealership technician, but left about the same time OBD2 came out - so my experience is quite dated. Still, some things never change! I bet most medium size dealerships still have only 1-3 technicians that really are good and do all the difficult diagnosis. The rest are parts changers that suck up all the easy work. Unfortunately the parts changers usually make more money when working on commission. After all, they can pick and choose their jobs by saying that they don't know how. I found that the more I knew, the less I made. I was working with the horrible computerized engineering abortions of the eighties! Back in 1985 I could really make those 1981 Caddy 8-6-4 V8s purr like a kitten and get 26mpg (you have to know how ridiculously troublesome these were). But not much call for that anymore! I digress......

Les

 

Thank you all. Appreciate it.

Turned out to be a vent valve after all; was only closing partially. Mechanic assures me the new part will solve the problem.

And yes--"Inexperienced" (or maybe just lazy and/or stupid as well as dishonest) mechanics seem to abound. The guy who looked at it today for me was thorough and was able to pinpoint the cause precisely.

Anyway, speaking of stupid...I'll pick the car up this afternoon and then make my way to Midas to get them to redo the new brake shoes they apparently had put on backwards last year (according to mechanic today who did a brake inspection).

I envy you guys who can do all this stuff yourself and avoid incompetent morons. Auto mechanics has just never been my thing and I wouldn't have time for it anyway.

Thanks again!

 

Hello RockyMountain,

I am only book smart. I can do a few odds and ends
on my own. I just like to gather in as much knowledge
as possible to help myself with trouble shooting and also
so that no one tries to pull the wool over my eyes. Its good
to know whatever you can. It helps in the long run.

I love the Blazerforum.

Mark

 

Yup, installing brake shoes backwards, or both primaries on one side, and both secondaries on the other, are all "rookie" / "no schooling" / "lack of experience" mistakes. That's one of the first things taught in automorive brake classes.

 

So Captain...First off, I agree with the other poster who complimented you for imparting so much knowledge. You helped me out with another issue a couple of years ago as well. Thanks.

On the backward brake shoes: I looked up my computer notes on this yesterday and I guess time had gotten away from me. Midas installed those shoes four years ago and the vehicle still seems to be braking okay. So what are the consequences of installing them backwards?

 

Thanks for the kind words, they are appreciated.

The primary shoe lining is shorter than the secondary lining.** The primary shoe POSITION is always toward the front of the vehicle. The primary shoe is applied first, then the secondary shoe applies. Due to a greater surface area of lining, the secondary shoe has a greater affect when stopping. If the shoes are installed backwards, the brake will be more sensitive on initial application due to the larger surface area of lining. If only one wheel is installed incorrectly, you might notice that it locks up before the other wheel. It's locking because the primary POSITION has more surface area. If both wheels are installed backwards you probably won't notice the locking as much because both wheels are contributing equally. Which gives you the false impression of "really good brakes".

** on most vehicles. Some vehicles use shoes with equal size lining.... Always an exception to the rule, so always check before installing them.

 

Thanks. I've never experienced any locking. Kind of think the person who installed them did all his brake shoes short to back and long to front, so my guess would be that he did both sides incorrectly.

Anyway, I just got off the phone with the manager of the Midas shop that installed them. He's already giving me every indication that he won't be amenable to giving me new shoes at no cost. He wants to charge me for labor. "100% at our discretion," he told me, given the fact that the shoes have been performing adequately for the last four years.

I disagree. I think he should replace the existing (backward) shoes at no cost.

Do you think I'm justified in calling Midas corporate to press for that and, if so, on what basis? That the shoes will wear out more quickly being in reverse positions?

 

As they say, "That's a Tuffy" In theory, you have them over a barrel due to improper installation. In this State, (Michigan) the BAR, (Bureau of Automotive Regulation) would be 100% on your side due to neglegence by the shop. I don't know if Colorado has anything like the BAR, but it would be worth looking in to.

Every automotive repair facility in Michigan must be registered with the State. Every technician must be certified by the State if they are paid to work on a vehicle that is registered and licensed to operate on Michigan roads. Damn good law for the customer, but certain things in the law, increases costs to the facility. Those costs are passed along to the customer in the form of higher labor rates and part costs. If the shop screws up, the State can, and does, come down hard on both the shop, and the technician, in the form of fines and suspensions in licenses.

 

I'll look into that for Colorado. Tx.