Kelsey Hayes Pulling Problem

Over the winter I put my 70 Duster back on the road, bringing it back after a 10 year hiatus in the back of the shop. One of the bigger items on the check list was getting the brakes in order. To that end I installed a new master cylinder, pulled and cleaned the proportioning valve, replaced all soft and hard lines, new rear wheel cylinders and rebuilt the front calipers (original 4 piston KH). I did go with Dot5 fluid this time so hopefully a long term setup won't cause problems down the road.

Imagine my surprise when after the above I hit the brakes a bit on it's first test test drive and the right front locks up.

So, back to the shop bleed it again, no change. What I've found is if I brake in a smooth controlled manner, no prob. But in an emergency type stop, it pulls a LOT to the right. I've checked the rears, they're adjusted properly.

Next on my check list is to pull the right front caliper and see if I can spot a problem. I was aware of the rolling a o-ring problem and took I though great care to not do that.

Any thoughts? All help is appreciated.

Thanks, Ron

sound like your left front is not working

Agree and I'd considered that. It's just that it seems to have plenty of fluid available when we bleed it. I verywell may be barking up the wrong tree though by focusing on the right side.

swap front wheels from left to right, try it out and report back

Every time I have seen this problem, it's been the opposite side. I have not seen a tire do this, but I have seen a tire create the pull in the first place, and braking would aggravate it.
So yeah, swap tires first, then dig into the other side. It may just be a pad hanging up or a contaminated pad. Leave the right for last; it is obviously working.
This assumes the combination valve is correctly plumbed,and correctly working.

Ok, to put the period on the end of the sentence.... I believe there were a couple of problems. One the brake hoses for the front had been on the shelf (my shop) for several years. For bonehead reasons, at one point in the total brake rebuild, I used vice grips to pinch the left front hose shut.

In pondering the above, I thought there was a possibility that by pinching the several year old hose I'd damaged it and even though it bled fine, there might be problems in real world braking. So, with that in mind I changed out both hoses.

I also readjusted the rear brakes, setting the left rear up several clicks.

Results, no pull. Since I didn't test each change I can't say which had the greatest benefit, but at the end of the day, I'm happy.

Thanks to all that replied.

RR

Congrats on a job well done.