Stepman

I have to agree with Thumpin here....I can't believe nobody brought up the hoses. They can get soft also and expand under pressure. Another thing to look at is the drum size. If there is a big difference side to side in drum diameter, it can cause a pull. (one may have been turned a long ways to get rid of grooves) Also, I have seen back brakes cause a pull that you would swear is coming from the front. 2 ways to eliminate the rears is to apply the park brake as you go down the road and see what happens....or clamp off the rear rubber line with vise grips and see if it still pulls.

Dtimekw

i am breech loading the front. all new springs, w/c, and hoses. i isolated the back brakes like you suggested (even loosened them way up) and the problem stayed in the front. I'll post once we are done.

Dtimekw

Well, we put all the new parts back on and still no joy. Same EXACT symptoms. I have to believe there is something in the suspension/alignment. Since the top of the driver's shock wants to go toward the firewall when I loosen the two mounting bolts, causing a caster issue (positive caster?) I will tackle that next. Any other ideas before I pull the drivers suspension down to parade rest????

On a good note, my son is learning valuable lessons regarding drum brakes

Stepman

Well, this is a tough one....a couple things bother me about this. I have read this so many times that it ain't funny...I have never seen a master that has the front res for the front brakes. On drum brake cars, any "proportioning" done, is done in the master. Proportioning is to apply the rears slightly ahead of the front's so that the vehicle doesn't go into a "nosedive". I would swap the lines on the master although I don't think this will cure your "pull".

It could also be in the suspension because the thing with the shock movement doesn't sound right but, I would think with the new bushings, you or your alignment guy would have seen something there...maybe something is bent somewhere. It seems that with all the work you've done, if the pull was from the brakes, it should've moved. Seems that you've changed everything except the tires.

Only one more thought. When you pull the drums off, do the brake shoes indicate the same kind of wear patterns?




Then again.....I may just have it all wrong..??

Dtimekw

I agree with you on the suspension. Something is not right. I did not flip tires but I did flip drums and the problem stayed on the drivers side. I've also always believed the front m/c goes to the rear wheels and rear m/c goes to the front but like you said, it wouldn't account for "pull". I think the alignment is still out even though he said he brought it in. I am going back next week (I have since replaced the bushings) and will have him go thru it again after I figure out why the shock thing is happening. I know I am going to find this but boy this has me going crazy.... Keep the suggetions coming, I truly appreciate everyone's help on this.

Gun Jam

- Step

Isnt the entire idea behind proportioning to match wheel lock up? for example we have about a 70% 30% split in braking work. The fronts do 70% of the work while the rears do 30%. When we add a disc (front) drum (rear) setup we have to further balance the barking work load so the rears dont lock up well before the fronts reach maximum energy burn. So using the proportioning valve we adjust pressure so the rears get less allowing the front to reach max energy burn at the same time the rears reach max energy burn. So now all 4 lock up and skid at the same time as the pass max work load. (of course it also allows us to pick front lock up a bit before rear if you wish)

Never heard the story about them being use to prevent "nosedive" how would that help any ways? weight is always transferred forward under deceleration....

-Gun

Gun Jam

Dude crazy idea!!!

the above rambling gave me a cool idea!

Find an open area (dirt or pavement) get the car going about 15 or 20 and apply rapid brakes to the point where you pass threshold and something locks up..

are you getting just one tire to skid or both the fronts or all 4? or some other weird combo like only right side skids.

having someone watch from the outside would be a good idea too one person watching the left side and one watching the right...video taping it for slow mo play back would even be better.

might lead to some new insight.

*EDIT**

Damnit I keep getting better ideas as I finish the first one

Just get the car going about 20 and ride the fricken brakes while maintaining 20 for about 10 or 15 sec. stop the car get out and use a non contact IR temp gun on all 4 drums and see if the fronts are near equal and rears are near equal then draw a top down pic of the car on a piece of paper and list the temp for each wheel and see if you notice a trend like right side is hotter than left side for both front and rear drums.
-Gun

Dtimekw

Gun - Way ahead of you. Did that the other night. Front left (driver) locks up real easy, no other tire(s) skid. I loosened the fronts and balanced the rears to skid evenly, then brought the fronts back into play. Front left locked up and pulled hard left. This is the part that makes me think the right front is messed up or needs to be bled.

Now that I am thinking about it, suspension wouldn't cause a "one wheel lock up". Hmm, Gun, you may be on to something here. The only other thing I can think of is to disconnect the TEE and attach each front line directly to the M/C (two ports).

Thanks Gun, you just kept me from going into left field....

Stepman

Now...you 2 have given me an idea....since we are already out in left field! Are you sure that your TEE is a "straight thru" tee and doesn't get reduced on one side?

Gun Jam

I highly recommend borrowing / renting / buying (best idea) a non contact IR temp gun. They are fairly inexpensive now days I think you can get a decent one around 40 to 50 bucks. You can use it for all kinds of stuff. Anyhow get one and do the temp measurement i described in the EDIT section of my last post. That will give you a far better idea of how energy is be used by the braking system.

-Gun