Front Drum Brakes Questions

[huss43]

I recently replaced the front drum brakes on my 75 Bronco. New Shoes, New Hardware, New Wheel cylinders, & New drums. Also replaced most of the poor looking brake lines. I had an issue with a little vibration coming from front driver wheel, could also feel it in the pedal.

I took off the drum to inspect and noticed that the foremost shoe was wearing but the rear shoe was obviously not making contact. Maybe a stuck wheel cylinder but this is brand new.

My first question is: Are the shoes different for the primary (front side) and secondary (rear side)? In looking at the ford repair manual it appears there is a difference in the amount of material on the primary shoe and secondary shoe.

Second Question: When I installed the new hardware kit with the springs. The two top spings are the same length and color. Is this correct? Again per the diagram the front spring should be shorter and go in the hole closer to the top of the shoe. I installed my spring in the lower hole just like the rear brake shoe on this side. So my two brake shoe springs that mount to the tops spud are the same, is this correct?

 

[skrit]

Just replaced mine too. The primary shoe is supposed to be the thicker/longer one and was told it goes on the rear since when braking the forward momentum puts more pressure on the rear shoe. Seemed like a good reason. Not sure about the spings though, can't remember. BTW, do your brakes pull when you put the brakes on sort of hard? I heard that is the way all front drums do.

 

[Broncobowsher]

The longer shoe goes to the rear. Part of the self energizing system. As the smaller primary shoe (front) creates friction it adds extra force through the adjuster to the larger (rear) secondary shoe. That extra force then goes up to the upper anchor pin that takes the force.

The wheel cylinder is double sided so the same action works when backing up as well. If you look at surge trailer brakes you will see the wheel cylinders are one sidded. This is so you can back the trailer up even when compressing the master cylinder on the tounge.

The springs are different. But I don't remember which one goes where.

 

[broncnaz]

Ditto broncobowshers post
The primary(front shoe) has the shorter lining. Some of the cheaper shoes nowadays come with the same size lining on both shoes. The thicker shorter spring goes towards the front but again I've seen some kits come with the same sized springs. Try to stick with bendix parts they are usually good quality parts.
It sounds like you have everything installed correctly. Part of your vibration problem may just be that they are new brakes and need to be burnished(ie worn in) the shoes and/or drum are not perfectly trued to each other when new. One way to burnish your brakes is to drive around maybe 20 MPH max and press the brakes then repeat do this 20-30 times and you should be good.

 

[72Sport]

The lining on some of the shoes are the same size but the primary shoes that I have seen have the lining shifted down so only part of it is in contact with the drum due to the way the brake shoe pivots when applying the brakes. I believe the last ones I used had the primary shoe shifted down about 1".

If you want to reduce the possibility of pulling to one side when you apply the brakes buy new Bendix shoes and lining not relined.

 

[huss43]

Thanks a lot for the info.

 

[TwoHorses]

SOB... hey guys... I just out new shoes on the front and my rig pulls really hard to the right. I found this thread and was hoping that it was because I had primary and secondary pads mixed up. Well by the looks of it... all the pads are exactly the same. Now what?

 

[stock74]

I just finished installing my new power brake kit and front wheel cylinder on the driverside since it exploded when I was bleeding the brakes. Now that I have the brakes bled my bronco pulls really hard to the right as well. I am pretty sure this problem can be fixed by adjusting the brakes. I have not adjusted the brakes yet so I do not know for sure.

 

[deltarat]

If all new parts and adjusted correctly it should not pull. I installed new brakes and hardware and I can hit the brakes without holding the wheel and it stops straight.

 

[stlkikn]

Of the last three front drum brake sets I have done, two were comprised of shoes that are the same size (primary and secondary) BUT were different colors of friction material.
The manufacturer had the shoes marked along the edge of the shoe as to location (prim/ sec) The difference in color is very noticeable, and mixing the shoes together will give you some very interesting braking reaction.

Properly adjusted brakes will not pull.

 

[deltarat]

After you drive it around a little, you may have to adjust them again after they get settled in. They do not have to pull just because you have drums.

 

[DirtDonk]

Also, if any air foung it's way into one side, then that side won't engage the shoes as firmly. Creating a pulling problem.
Same thing for mis-adjusted wheel bearings or contamination (oil, grease, brake fluid) on the shoes or, as mentioned, shoes that are not adjusted evenly from side to side.

Paul