Turner disc brakes

[Hogtrough]

My OEM discs were frozen due to many years of unuse, so I elected to modernize with the much larger Turner disc kit (all lines and hoses replaced too, and rear drums checked and adjusted) . On Jim's advice, I didn't install a proportioning valve, but wonder if I might need one. Car veers heavily right on a hard stop and I think it may be the rears causing this (often described as wanting to "swap ends"). I think it would be downright dangerous on a slick road, so wondering if I need to have the rears doing less by installing a variable proportioning valve. 

[Dwight FitzSimons]

What you're describing is the rear brakes locking up, causing the car to swap ends.  In other words, the rear brakes are providing (proportionately) more braking force than the front.

But, think about it, if the rears didn't lock up with the Bendix/Dunlop brakes then why would they lock up with the Turner brakes (which provide more braking force than the old disc brakes)?  The answer is that they couldn't.

You have something seriously wrong.  I would go through the complete brake system and make sure that everything is correct.

A couple months ago I had my mechanic convert my '64 Avanti's disc brakes to the Turner system, and install his dual master cylinder kit.  Everything worked out perfectly and the car has strong brakes that stop the car straight.  I am quite happy with Turner's brakes & MC.

--Dwight

[Gunslinger]

Your rear brake wheel cylinders may need rebuilding…one may be frozen, a leaking seal or a bad hose.  Don’t go adding something that may not be necessary.

[John Brissette]

Why don't you call Jim and, find out what he thinks the issue could be.

[EnduroDriver]

You mentioned Jim didn't recommend adding a proportioning valve. Is that because you already have the dual circuit master cylinder?

When you say the car veers right does that mean the front of the car goes right or is the right rear trying to come around on you? 

I did the Turner kit up front, dual master upgrade and all new rear drum brake components. Car stops great, straight as an arrow.

[Hogtrough]

13 hours ago, EnduroDriver said:

You mentioned Jim didn't recommend adding a proportioning valve. Is that because you already have the dual circuit master cylinder?

When you say the car veers right does that mean the front of the car goes right or is the right rear trying to come around on you? 

I did the Turner kit up front, dual master upgrade and all new rear drum brake components. Car stops great, straight as an arrow.

 

He made the recommendation based on experience with his own cars, which never seemed to need a valve. Mine distinctly feels like the rear trying to come around, rather than the right front grabbing. Maybe I need to re adjust the rear brakes. I bought the dual master along with the kit

 

 

[mfg]

1 hour ago, Hogtrough said:

 

He made the recommendation based on experience with his own cars, which never seemed to need a valve. Mine distinctly feels like the rear trying to come around, rather than the right front grabbing. Maybe I need to re adjust the rear brakes. I bought the dual master along with the kit

 

 

The Avanti factory installed a proportioning valve on their 1983 models… However, (I think) they used it because the rear drum brakes on the ‘83’s, although the same size as the rear brakes on Studebaker Avantis, were self-energizing and had more stopping power.

[Guy]

It couldnt hurt to rebleed the brake system, or for that matter pull drums and be sure you dont have a leaking brake cylinder getting the shoes wet

[Zedman]

My Avanti II 1981 model had the Kelsey-Hayes Proportioning valve on it and orignal Bendix Calipers when I broke the car down for frame off resto.  Because the K-H unit is a bit of a rarity and hard to replace parts for, I decided to go with a brass GM PV2 proportioning valve . This valve is specifically for Disk & Drum combination and is a bolt-up replacement for the K-H valve.  From what I have researched, a proportioning/combination valve is there for the purpose of allowing the rear brake drums to apply just ahead of the front Discs- that's all. This is to prevent the front brakes propping, and causing the rear end to 'come around'. For this reason, I wouldn't fob off the idea of using a combination/ proportioning valve.  I wonder whether you might have a an issue with the right rear brake applying with more gusto- causing a right hand veer.  May I suggest checking the orientation of the Shoes, adjustment of the shoes, the condition of the rear Flexible brake line (they are often blocked- like mine were), the condition of the brake lines along the rear Axle (I found mine crushed !) and condition of the rear brake cylinders. After that, maybe look at utilising a propvalve?

[Hogtrough]

21 hours ago, Zedman said:

My Avanti II 1981 model had the Kelsey-Hayes Proportioning valve on it and orignal Bendix Calipers when I broke the car down for frame off resto.  Because the K-H unit is a bit of a rarity and hard to replace parts for, I decided to go with a brass GM PV2 proportioning valve . This valve is specifically for Disk & Drum combination and is a bolt-up replacement for the K-H valve.  From what I have researched, a proportioning/combination valve is there for the purpose of allowing the rear brake drums to apply just ahead of the front Discs- that's all. This is to prevent the front brakes propping, and causing the rear end to 'come around'. For this reason, I wouldn't fob off the idea of using a combination/ proportioning valve.  I wonder whether you might have a an issue with the right rear brake applying with more gusto- causing a right hand veer.  May I suggest checking the orientation of the Shoes, adjustment of the shoes, the condition of the rear Flexible brake line (they are often blocked- like mine were), the condition of the brake lines along the rear Axle (I found mine crushed !) and condition of the rear brake cylinders. After that, maybe look at utilising a propvalve?

All brake parts except for shoes are new, and the shoes look recently replaced. I tried slamming on the brakes in a parking lot and looked at the tire stipes. The left rear was nowhere near as strong, barely there. So I'll try re adjusting it.