1987 Chev van brake fluid restriction

Looking for a little advice.
My Chev passenger van (1987) is getting older and more problems cropping up.
The last few months the brakes have been pulling to the left on hard braking.
It is felt noticeably in the steering wheel, so that is why I'm pretty sure its because the right front isn't sharing the load.
So I have been trying to track down the cause but no solution so far.
All the steering and suspension components are in fair shape, wheel bearings snug, changed out the rotor and caliper on right side with a better set from a wreck, bled system all around a couple of times over the months. No luck yet!!!
What I did notice today was that the fluid flow to the right side is much more restricted than the left(my son was pushing the peddle before and I was doing it today, so I took immediate notice of the different resistance.)....I would think they should be equal.
What is the best way to track this down?
Keep opening each brake line connection back to the master cylinder or is there something in the proportioning valve that should/can be re-centered??
I don't have a shop manual for the van, but I never had a problem like this doing the brakes before. I've had it 18 years, hoping to get a few more yet if its willing, and I can handle these problems in the backyard.

Looking for a little advice.
My Chev passenger van (1987) is getting older and more problems cropping up.
The last few months the brakes have been pulling to the left on hard braking.
It is felt noticeably in the steering wheel, so that is why I'm pretty sure its because the right front isn't sharing the load.
So I have been trying to track down the cause but no solution so far.
All the steering and suspension components are in fair shape, wheel bearings snug, changed out the rotor and caliper on right side with a better set from a wreck, bled system all around a couple of times over the months. No luck yet!!!
What I did notice today was that the fluid flow to the right side is much more restricted than the left(my son was pushing the peddle before and I was doing it today, so I took immediate notice of the different resistance.)....I would think they should be equal.
What is the best way to track this down?
Keep opening each brake line connection back to the master cylinder or is there something in the proportioning valve that should/can be re-centered??
I don't have a shop manual for the van, but I never had a problem like this doing the brakes before. I've had it 18 years, hoping to get a few more yet if its willing, and I can handle these problems in the backyard.

Have you checked the rubber brake hose for restriction?

Thanks for the reply MT-2500.

Took another crack at it this morning and sure enough it was the rubber flex hose that was the problem. I think I replaced it 10 years ago. It looked fine on the outside but something is wrong on the inside that cuts the flow in half. Replaced it and I've got a big smile on my face now that I can brake evenly. The old beast is a pleasure to drive again. Love those simple fixes,.. but this one had me guessing for awhile that's for sure.

Thanks for the reply MT-2500.

Took another crack at it this morning and sure enough it was the rubber flex hose that was the problem. I think I replaced it 10 years ago. It looked fine on the outside but something is wrong on the inside that cuts the flow in half. Replaced it and I've got a big smile on my face now that I can brake evenly. The old beast is a pleasure to drive again. Love those simple fixes,.. but this one had me guessing for awhile that's for sure.

You are welcome and thanks for posting back the fix.

The other one may be getting bad to.
Also helps to flush the old brake fluid out every 50K or 3-5 years.
Good Luck