Topic: Front Brakes Draging

[skane1970]

Hi Guys....

I have a 1980 GMC Vandura 35 class C RV that has a brake issue of some sort.
The brakes are working just fine until the system heats up and then the front brakes begin to drag so much that the engine  has to really work to move.You let RV sit until cool and the the same thing happens again.What could be the issue
Thanks in advance fore any help that you can give.

[Sir Osis of Liver]

Sounds like sticky callipers, assuming it has front disks. If it sits for a while the brakes may release. Once used, they may be slow to release.
You can get the same kind of problem with drums if you have rusted parts, weak springs or bad wheel cylinders.

[skane1970]

I am just wondering if it is possible for both calipers to be acting up at the same time??Could this be bad wheel bearing??
I have taken both calipers off and sprayed them carefully around the rubber and let them sit but  when I put them back on and took the rv for a test drive nothing changed and the front brakes are still draging.
I am also wondering ifit could be the flex lines??An old GM mechanic I know said that he replaces many faulty flex line over the years.

[rrocket]

I am just wondering if it is possible for both calipers to be acting up at the same time??Could this be bad wheel bearing??
I have taken both calipers off and sprayed them carefully around the rubber and let them sit but  when I put them back on and took the rv for a test drive nothing changed and the front brakes are still draging.
I am also wondering ifit could be the flex lines??An old GM mechanic I know said that he replaces many faulty flex line over the years.

Spraying oil will do nothing to fix a tight caliper. Replace.

To find out which caliper is dragging, go for a good drive then touch the front wheels with your hand. Whatever wheel is piping hot is the one the caliper is dragging on

[skane1970]

I took the rv out for a drive and when I got home I jacked up the front end and neither wheel will spin.They are seized but when she cooled down again the wheels would spin with no effort at all.

[Sir Osis of Liver]

I took the rv out for a drive and when I got home I jacked up the front end and neither wheel will spin.They are seized but when she cooled down again the wheels would spin with no effort at all.

Yup. That's how it goes. Time for some re-manufactured callipers, new pads, discs and brake fluid.

Some people go with turning the discs, but I never found that to work out well long term. The discs are thinner and end up warping especially in heavy use.

[Fobroader]

I took the rv out for a drive and when I got home I jacked up the front end and neither wheel will spin.They are seized but when she cooled down again the wheels would spin with no effort at all.

Yup. That's how it goes. Time for some re-manufactured callipers, new pads, discs and brake fluid.

Some people go with turning the discs, but I never found that to work out well long term. The discs are thinner and end up warping especially in heavy use.

I agree, seeing how its an old GM it shouldn't be too expensive.

Sent from my Galaxy S3

[PJungnitsch]

I am also wondering ifit could be the flex lines??An old GM mechanic I know said that he replaces many faulty flex line over the years.

It can be, I've heard of the rubber lines closing up to the point they become one-way valves. Pressure from the brake pedal will get through to close the pads, but the return pressure from the caliper isn't enough to open them again. The brake fluid will bleed slowly, releasing the brakes after the car sits for a while.

That said, it's not a bad idea to change at least the calipers as well.

[Sir Osis of Liver]

I am also wondering ifit could be the flex lines??An old GM mechanic I know said that he replaces many faulty flex line over the years.

It can be, I've heard of the rubber lines closing up to the point they become one-way valves. Pressure from the brake pedal will get through to close the pads, but the return pressure from the caliper isn't enough to open them again. The brake fluid will bleed slowly, releasing the brakes after the car sits for a while.

That said, it's not a bad idea to change at least the calipers as well.

That's true. On a vehicle that old, the lines are probably due as well.

[skane1970]

I am just wondering if there is a way to test the flex lines to see if they are still working properly

[rrocket]

I am just wondering if there is a way to test the flex lines to see if they are still working properly

Brakes are no place to cheap out. Just put new lines in at the same time.

[Fobroader]

I am just wondering if there is a way to test the flex lines to see if they are still working properly

If those brake flex line are original, they are almost 35 year old rubber components, get new ones.

I am just wondering if there is a way to test the flex lines to see if they are still working properly

Brakes are no place to cheap out. Just put new lines in at the same time.

Absolutely!!

[skane1970]

I am not sure if the are the originals but I will start by putting new pflex hoses on and put new oil in the system and hopefully my brakes will be good as new again.It has good rotors and new pads already

[skane1970]

New flex hoses are $27 each so that is pretty cheap

[jamie1]

I am not sure if the are the originals but I will start by putting new pflex hoses on and put new oil in the system and hopefully my brakes will be good as new again.It has good rotors and new pads already

In "oil", I hope you mean brake fluid! They are not the same thing. If there is oil in the system now, that could be a cause of your problems.

[skane1970]

Yes I ment to say brake fluid (DOT 3)I just say oil.

[skane1970]

Hi guys.......

My front brakes on the rv are fixed.....
I replaced both front flex hoses and flushed braking system with new brake fluid and now she workes great.
Thanks for everyones input.

[Sir Osis of Liver]

Hi guys.......

My front brakes on the rv are fixed.....
I replaced both front flex hoses and flushed braking system with new brake fluid and now she workes great.
Thanks for everyones input.

Great news. I like a happy ending! 

[rrocket]

Hi guys.......

My front brakes on the rv are fixed.....
I replaced both front flex hoses and flushed braking system with new brake fluid and now she workes great.
Thanks for everyones input.

Great news. I like a happy ending! 

Especially when it's a massage, eh?