Curts1970cutlass

Hi Just wondered if there was a step by step for removing the front drum set up as well as installing the front disc setup. Have the disc setup from a 72. Also saw that on some vehicles the torque specs are for when full weight is on wheels. Is this the same for My 70. As its on jack stands now.

Thanks

TripDeuces

Yes you want the weight sitting on the A arms when you tighten everything.

joe_padavano

Actually, that only applies to the bolts holding the rubber bushings on the suspension arms. If you are only changing the spindles at the ball joints, it doesn't matter as far as torquing the ball joint nuts. You will find, however, that having the suspension at ride height (by having the jack stands under the springs) will improve access to the ball joint nuts. And even if you leave the shocks in place to keep the springs from coming out, you will still need to compress the springs somewhat to get the ball joint nuts started.

Olds442redberet

I did the same swap last weekend. It's easy. It's quick. It's a DIY job.

The biggest issue will be the ball joint removal. And yes, you'll most like want to do this at the same time. You are going to damage the boots and the ball joints are probable old and worn out anyway.

I also bought a new master cylinder for the car I pulled the brakes off of, instead of using the old one from the same parts car.

I pulled the whole assembly as a unit and installed it as a unit. I had a low milage donor car. I had to bust one steering knuckle per side and two ball joint knuckles per side.

I'll replace the bearings, brake pads, and disc at a later date. If needed. Most likely I will just grease the bearings next weekend.

The new disc brakes work great.

1971cutlas

Did you use the existing proportion valve from the drum brake car(frame mounted)?,
Or did you get a different prop valve for "disc brakes".Also Frame mounted?
Or a new disc brake proportioning valve mounted up close to the master cylinder?
Sorry to hijack thread ,but i am switching my 71 cutlass s to front disc and
(INLINE TUBE ) sold me a prop valve to be mounted close to master cylinder!!
I am doing a "frame off""resto ,and will be attacking this area soon!!

Olds442redberet

You need the proportional valve from the car your pulling the brakes from. The 68 to 72 cutlasses are pretty much the same weight across the board. But I actually didn't use the proportional valve and I didn't have any issues. But I was, and still am, prepared to correct any issue related to the proportional valve should it pop up.

I changed the front brakes and the master cylinder and gave it a test drive. But not recommended.

joe_padavano

GM used both designs. The 1967-1970 disk brake cars used the metering valve that mounts under the master cylinder in conjunction with the distribution block on the frame. The distribution block was the same for drum and disc cars and does two things. It distributes the two outlets from the M/C into separate front right, front left, and rear pipes, and it also houses the differential pressure switch that lights the BRAKE light on the dash if you lose pressure in one half of the brake system.

Starting with the 1971 model year, GM combined these two separate parts (metering valve and distribution block) int the aptly named COMBINATION valve, that replaces the distribution block on the frame for disk brake cars. This was purely a cost savings measure, since it's cheaper to install one part on the assembly line instead of two. Either configuration works fine.