1992 Camry Difficulty Bleeding Brakes

[Techventure]

I replaced my rear brake proportioning valve and had difficulty getting proper pressure back in the hydraulics. After attempting to bleed them myself which I have successfully done in the past I decided to take it to a mechanic and have him do it in an hour or so.
This exercise turned into 10 days in which 3 used master cylinders were tried and 2 re-manufactured, ending up with a re-manufactured because it would have been more labour to remove and put my original back on which turned out to be fine. A used vacuum booster was tried, then a used actuator pump and still no brakes.

Today we were told it was fixed and they had found the rear calipers were reversed on the rear wheels and the bleed ports were pointed down and they should have been pointed up and because of this air was trapped behind each piston causing the pedal to drop. I had replaced one of the calipers a year ago with a used one and I installed it as per how the original one was installed.......the flexible hydraulic line screwed into the caliper with the little lead in pin going into the line-up hole. The other caliper has never been removed from the flexible hydraulic line since I have owned the car from 1997 and the original owner never had any brake work done as I have all the maintenance records.

Therefore, I have a mystery on my hands!!!!

My first question to you folks is this. If the calipers were reversed and the bleed ports were pointed down as the mechanic stated and not up, would this really make a difference in bleeding the brakes????? I installed a number of hydraulic systems during my engineering career before I retired and I have mainly done all my own car maintenance and I am having trouble accepting this story.

The second question at this time. All these attempts with solving the problem with different master cylinders, replacement booster, a great amount of hydraulic fluid used and shop labour solving the problem which to me was not handled properly from the start......should I have to pay for all of this? If the job had been tracked down wheel to wheel in the first place all this unnecessary trial and error would not have occurred. The mechanic did not proceed step by step and was floundering.

A job which at the most, I would say would be a hundred $$$$'s, has turned into $650 including taxes. I have paid him half at this time. I want to be fair about this.

Your input and comments would be appreciated.

[Brian R.]

For my own edification: When you originally had trouble trying to bleed the brakes after installing the proportioning valve, would you have noticed if the calipers were reversed, or whether one of the calipers was the wrong one (both sides of the car had the same caliper, one upside down)? What was the trouble you had in bleeding the brakes initially?

Is it possible you replaced the caliper a year ago with one from the wrong side? I don't know if this is physically possible. Never tried. If it is, the hydralic line may be centered vertically in the caliper, so that you don't notice that you have the wrong caliper when you attach it.

In answer to your question: If the calipers where switched, it is likely that the bleed screw is in the wrong orientation relative to the wheel cylinder to bleed it correctly. The bleed fitting or the passage from it to the wheel cylinder would have to be on the top of the wheel cylinder to get all the air out. Switching the calipers from side to side would place the fitting or the passage on the bottom, and yes, make it impossible to bleed the brakes.

Did they say that they had to switch the calipers to fix the problem, or did they just blow the explanation off with no real details? Did they charge you to switch the calipers or replace the one caliper that was wrong? If what they say is true, they should have charged you to switch the calipers, or replace the wrong caliper. If they never did, it sounds like they are blowing smoke.

Very strange. I would like to hear more about this before I pass judgement on how much you should pay....