Dino Saga 051106 Sounded and felt like the right rear tire was flat. I was going about 80 so slowed down, pulled off road and took a look. Tire looked fine so I felt the wheel. Hot. Touched the brake disk and lost some fingerprints. Really hot! Got back in car and slowly drove to a spot where I could lift the wheel. My trusty scissors jack worked fine and I turned the wheel. Felt fine. Parking brake cables were loose. Curious. Got back in car and drove carefully for a week when suddenly got the flat tire sounds again. Same scenario. By the time I got stopped and jacked, all OK but again really hot. Now time to get serious. Brought car home and put it up in the air. Removed wheel and spun disk. Free as can be. Pressed on brake pedal and pads moved in just fine. Let up and they did not retract very far. Maybe pistons are sticking. Had changed pads a number of times but never removed pistons. Caliper had never been apart as far as I know. Ordered a set of seals, pulled caliper and took a look. Piston oil seals looked good, dust seals shot and a little dust in bore. Saw no signs of anything wrong but replaced all rubber and put back together. Bled a lot of oil just to look at oil color. No problems. Put everything back together and it drove fine. 3 weeks later, back to hot disk, grabbing. Called guys at GT Car Parts and asked if they had a replacement caliper. Yes, $500 for a re-built one. Is it returnable? There will be a re-stocking charge if no damage and in original box. Well, why not. Next day I changed caliper. Pads still did not retract fully. Caliper was not the problem, oil pushed just fine, would not go back. Finally took a close look at the brake hose. Tried to run a steel rod down the hose ID. Got about 1 and felt resistance. Pulled rod and got a few rubber particles. Tried again. More rubber bits. Hose was full of small rubber particles: inner rubber had disintegrated. Outside of hose did not look too bad but was slightly bumpy and had a coating of oil and dust. Looks like spilled oil from changing the oil filter had periodically coated the hose. Did not do much to the outside but had played havoc with the bore. Oil under hundreds of pounds of pressure could go through fine but there was nothing pushing the oil back through the maze. It would go back eventually but if you were driving, one touch of the breaks would start a chain reaction where things got hot, everything would expand, things got hotter and the wheel would rather not turn. Called GT, explained situation, ordered a pair of new hoses and got OK to ship caliper back. Re-stocking charge was reasonable and a new hose went on right rear with original caliper. Bled everything and By George, the pads pulled back just fine. I tried to replace the left rear line while the car was up in the air. That hose looked like new; but better safe Got the hose loose at the caliper but could not get the other end free. Gave up, put all back together, bled everything again and went out to drive. Problem was cured and all has been right with the brakes for more than 5 years. Some day I will replace the left hose; some day. Some fixes require a little bit of playing Sherlock Holmes. I now put a plastic bib underneath the oil filter when I change it. Undoubtedly helps the suspension bushings too. You learn. John Image Unavailable, Please Login Image Unavailable, Please Login
Well done on finding the faulty part and sorting out the problem. A sticking brake caliper is a weird thing, Ive had a few, including one on a borrowed 275, but all of them were caused by a faulty valve in the brake system, not by dud hoses. The law of unintended consequences..... Who would have thought that an oil change could alter the performance of the braking system? I enjoy your writing - keep it up!
Mark and John - I suspect that the hardening of the arteries is more likely a consequence of age and brake fluid versus oil on the outer surface. I have had the same thing happen without evidence of oil contamination. John - keep those experiences flowing. I, too, have many thousands of miles on my 3 Dinos, and have completely restored a greater number. Your comments have been right on. Thanks. Jim S.