72 corvette roadster

I have replaced all 4 calipers with VB&P Stainless Steel sleeved O-ring calipers, and at the same time replaced all rubber lines with VB&P lines. All lines have been sufficiently bled, however the front brakes seem to drag significantly. The previous owner replace the Master Cylinder with what appears to be the correct part (this is a non-power brake car). I have noticed while driving that the car does will roll freely on a grade, and today on the jack stands the front wheels are difficult to turn. The rear wheels do not seem to affected. Any ideas as to why the fronts are dragging so much?

427V8

is your push rod adjust properly and not pressing the MC?

oldalaskaman

I dont have any experience with VB&P , so this is a generalized suggestion. Those o-rings also called seals by some are directional. When they are installed correctly, they have a very slight raised lip that has to be facing inboard, towards the center of the car. It acts like a spring and when the brake pedal is released, it moves the piston slightly back in the bore releasing pressure on the pad allowing the wheel to spin freely. If those seals are facing the outboard, away from the car, they will keep pressure on the pad and keep the wheel from spinning freely. if thats the only parts you changed and they worked before you installed them I would look there first. hope this helps

gingerbreadman1977

I would agree with this one. Also in another car i bought a chrome booster(for looks) with the pushrod and brackets etc and it also dragged no matter where i adjusted the pushrod. I went back to my original booster and the problem was gone.

1427

Did you replace the flex hoses? Sometimes they collapse. I had this problem and went with D.O.T. rated braided lines and problem was gone

mrvette

THIS, happened to me, left side got SO hot I had to rebuild the caliper and replace both front rotors, some years ago, now if I pull into neutral the car will coast out of the garage.....

oldalaskaman

if ...his mc worked fine prior to the parts change, and he didnt do anything to it, it should work fine now.


any of you folks actually read his'entire' post?

Mike Ward

Ya, I did and the folks that are pointing towards the M/C or pushrod are correct. This is a good starting point. One easy trick is loosen off the nuts holding the M/C to the booster or firewall. If the wheels become easier to turn, the source is confirmed.



On the other hand, your understanding of what an o-ring seal is vs. the standard lip seal is way off the mark. The o-rings are omnidirectional and it doesn't matter which way they face. The statement that the raised lip type seal has to facing inboards towards the centre of the car is absolutely incorrect and possibly dangerous if someone were to follow your instructions.. This rule might apply to a single piston floating caliper, but certainly not to a four piston fixed caliper. The raised lip must face towards the brake fluid which would put half the seals facing outboard. The seals will most certainly leak if installed backwards.

You should know also, that the C2/C3 caliper contain a spring behind each piston to ensure that the pad stays in contact with the rotor at all times, even when the brake pedal is released. This ensures minimum lag time in brake application time as well as a high and firm pedal. Bubba has been know to remove and toss these springs not knowing what they're for.

Easy Mike

Define "dragging." Corvette brake pads are in contact with the rotors at all times. There is always drag. How much drag do you have?

oldalaskaman

I understand the differences , just dont have experience with the product he installed. He didnt change the mc, only his front brakes drag, he changed his hoses, why make this a rocket science thread when its not? you quote good and read good, but having him do something just for your entertainment is not cool.

oldalaskaman

you providing all this info is good, but he would like an answer to his issue, not you venting something you read, he didnt change anything but the parts he mentioned, it would have been good if you had provided VB&P tech. but you generalized mess is unfortunate. you are right about the seals facing though, I should have said , towards the cylinder. picky, picky.

72 corvette roadster

It is difficult to turn the front tires by hand when on jack stands-the rears turn fairly easily. I have noticed as well that the car will not roll freely on a slight grade (need to be on a big hill for it to roll).

Mike Ward

Quick and obvious answer- your long, pointless post on caliper seals contained a considerable amount of incorrect advice and dangerous information. Some new guy might just read it and follow your advice.

72 corvette roadster

Also, I cracked open the bleed nipple on one the LF and lightly pushed back the pads (resulting of course in a bit of fluid coming out) and then it turned very easily...

oldalaskaman

actually not, I've re-done other 'brake experts' mistakes so much that I automatically go to the parts they worked on first. I was explaining how they worked to an inexperienced member so he might under stand the operation. go get your coffee, and play nice, I'm having mine now.

oldalaskaman

next time you do all that reading , read for understanding...or have some one explain it to you

Mike Ward

That makes sense, but doesn't establish why the pressure is being trapped. Put the wheel back on and recreate the hard to turn situation of you can. Try loosening the m/c nuts a few turns as suggested above and see what happens.

oldalaskaman

best would be to contact the rebulider and ask them, I'm sure its something simple and not anything you did

oldalaskaman

this doesnt explain his constant pressure or any kind of a solution, you have a good heart or you wouldnt be so opinionated

DANNYS8

Will someone clear this up for me.My present vette (82) and a number of my past c3's,the front tires when the car is on a lift (or jack stands) would not exactly spin freely.Actually the wheels would only spin as far a I push them not any more.There would be resistance,not much but the wheels would hardly freespin like 2,3,4,5 times extra when I push them like other cars.Is this normal?