2008 F-53 Chassis

[Mr__Steve]

Any ideas on reason for my motorhome to pull to left when I brake. I have new tires, had front end aligned, new brake pads. Thanks!

[tropical36]

10forty2 wrote:
Tire pressure, bad tire, a dragging brake, out of alignment....all will cause a constant pull to the offending side. If it only happens when you brake, then it tends to reason that the brakes on the pulling side is grabbing harder than the other side. That may mean that the caliper on the opposite is NOT grabbing at all, or is not grabbing as hard. Why? stuck caliper is my first guess. If you serviced the brakes and didn't service the calipers by cleaning/greasing the guide pins, then they may be sticking instead of moving the pads towards the rotor. The pads themselves (on the opposite side of the pull) could have a glaze on them if they weren't broken in properly after installation and even though they are compressed against the rotor, they may not be grabbing it. And like said above, the hydraulic line on the opposite side of the pull may be collapsing or have trash in the line blocking it from transmitting the pressure to the caliper. Where could the trash come from? Maybe from the inside of the line deteriorating...maybe from contaminated fluid... Best bet is to pull the brakes again and check things out.

In my experience, transmitting pressure to the caliper wasn't a problem with an internally collapsed hose, it was with the fluid returning to the master cylinder, creating a drag and on the left side, like the OP. Again, it didn't require braking for it to drift in that direction, once you let go of the steering wheel.

[10forty2]

Tire pressure, bad tire, a dragging brake, out of alignment....all will cause a constant pull to the offending side. If it only happens when you brake, then it tends to reason that the brakes on the pulling side is grabbing harder than the other side. That may mean that the caliper on the opposite is NOT grabbing at all, or is not grabbing as hard. Why? stuck caliper is my first guess. If you serviced the brakes and didn't service the calipers by cleaning/greasing the guide pins, then they may be sticking instead of moving the pads towards the rotor. The pads themselves (on the opposite side of the pull) could have a glaze on them if they weren't broken in properly after installation and even though they are compressed against the rotor, they may not be grabbing it. And like said above, the hydraulic line on the opposite side of the pull may be collapsing or have trash in the line blocking it from transmitting the pressure to the caliper. Where could the trash come from? Maybe from the inside of the line deteriorating...maybe from contaminated fluid... Best bet is to pull the brakes again and check things out.

[wildmanbaker]

I believe that Hank has the answer. Twisting or kinking the brake hose during service can cause what is happening to the OP. Just because the outside of the brake hose, or cooling hoses look good, does not mean that the inside is good to go.

[Hank_MI]

John&Joey wrote:
...bad brake hose, blah blah blah would pull all the time.

Not true. If the inner lining on the right side hose is cracked it can flip up and block pressure to the right caliper causing it to pull left. Let off the pedal, pressure on left caliper is released, wasn't any on right caliper, and pull goes away. The opposite can also happen. That is the loose inner lining can keep the pressure to caliper up after you've let off the pedal. This would cause it to pull to that side after releasing the pedal.

Don't know if the pull was there before the new pads or not. Changing brake bads is the perfect time to ruin a brake hose. If the caliper falls or gets twisted around too much while replacing the pads you can easily ruin the hose.

BTW: I do know what I'm talking about and have experienced this problem. New pads, good calipers, new pins, still pulled. Took it to several shops, surprised they didn't suggest hoses, but they said the brakes were perfect. I finally replaced both hoses and problem gone.

[fourmat]

Likely a sticking or bad caliper on the opposite side of the pull also brake hoses are suspect you can look and see if any have a bulge when brakes are applied. However get it checked right away.

[allbrandauto]

most brake pulling problems the problem is on the opposite side of the pull

[wolfe10]

5 years on brake fluid is likely fine if most of your driving/storage is in a dry or desert area.

3 years is a better interval if in "non-dry" areas.

[garyemunson]

A 10 year old RV is VERY likely to need new calipers especially if has spent a lot of time sitting between outings and the brake fluid hasn't been flushed at least every 5 years. That's the interval I have gotten in the habit of using. Since I started that maintenance regimen, I have yet to need a replacement caliper on ANY of my vehicles. After 5 years the fluid will come out slightly darker than the new fluid. Flushing something that has gone longer than that will produce fluid that looks like root beer.

[Dale_Traveling]

Try the temperature test but check the right side very closely. Could be rather than a dragging brake but just the opposite in that the right isn't braking enough. Since the caliber pistons have to be pressed back into the housing when replacing the pads might be something to consider. Also the slide pins on right might be binding prevent the caliber from clamping effectively.

If the brake fluid was replaced try bleeding the right again. A bubble in the right caliber might cause soft braking on that side but you might feel it in the pedal.

Third, swap tires left to right or front to back. A bit of a Easter Egg Hunt but pretty easy to do.

Fourth, new pads do take a bit of time to wear in. Particularly if the disks are original and were not resurfaced.

[John_Joey]

The man said "when I brake." Now why would I not believe him?

Low tire pressure, bad brake hose, blah blah blah would pull all the time. Only real odd ball thing might be a rotor with soft spots on it. Doesn't happen often but does happen and will also catch when you brake.

Man said he replaced pads, not calipers or rotors. Didn't say anything about cleaning up the pins on the calipers or doing any sort of PM on them or even resurfacing/replacing the rotors.

To the OP rule out a dragging brake shoe. It's cheap and easy to do. If you don't want to buy a thermo gun then just use your palm on the center of the hub. Be careful not to burn yourself.

A dragging brake shoe is the most common cause of pulling when you brake. Hope this helps.

[tropical36]

John&Joey wrote:

Mr Steve wrote:
Any ideas on reason for my motorhome to pull to left when I brake....

Your brake shoe is dragging. You replaced the shoe's but not the caliper is what I'm betting.

Go to Harbor Fright and buy a cheap thermo gun. Shoot each rotor after driving around a bit without braking. See if one is running hot.

Ya know, with all the theories being presented here, let's keep in mind, that in most of these cases, the rig will pull to the affected side, whether you're braking or not, so maybe that distinction should be made first.
Had a collapsed brake hose once on our old gasser and after a while it would loosen up, but just one stop and it would drag and pull for a good bit, braking or not and until the fluid, slowly worked it's way back to the master cylinder and thereby releasing the caliper.

[John_Joey]

Mr Steve wrote:
Any ideas on reason for my motorhome to pull to left when I brake....

Your brake shoe is dragging. You replaced the shoe's but not the caliper is what I'm betting.

Go to Harbor Fright and buy a cheap thermo gun. Shoot each rotor after driving around a bit without braking. See if one is running hot.

[tropical36]

DrewE wrote:
tropical36--are you referring to tire air pressure as the first thing to check? I think the F53 uses (and has always used) hydroboost brakes, rather than air over hydraulic of some sort, so that's the only somewhat relevant air pressure I can think of.

In my experience, a sticky brake caliper can feel like a pull to the opposite side when braking, when it's more accurately a constant pull to that side all the time...so check your right brakes as well as the left. Motorhome brake calipers are somewhat prone to getting sticky since they tend to sit unused for rather lengthy periods of time and possible accumulate corrosion etc. There are, of course, other causes of sticky or intermittent braking.

Yes, low tire pressure, of course and the rig will pull in the direction of the tire that is low, due to friction or dragging for some reason.
As for brake boost, yes and one and the same as the power steering pump on a gas coach. There are some air over hydraulic systems on DP's too.

[DrewE]

tropical36--are you referring to tire air pressure as the first thing to check? I think the F53 uses (and has always used) hydroboost brakes, rather than air over hydraulic of some sort, so that's the only somewhat relevant air pressure I can think of.

In my experience, a sticky brake caliper can feel like a pull to the opposite side when braking, when it's more accurately a constant pull to that side all the time...so check your right brakes as well as the left. Motorhome brake calipers are somewhat prone to getting sticky since they tend to sit unused for rather lengthy periods of time and possible accumulate corrosion etc. There are, of course, other causes of sticky or intermittent braking.