Rear brake upgrade questions

[Big E]

I installed the EGR rear drum brake package a few weeks ago. I was wondering if anyone who has the same package has had a problem with the brakes being grabby at slow speeds? This is not a "flash rust" problem, as it happens all the time, not just in the morning. I'm talking speeds below 3 to 5 mph. I'm getting tired of leaving chirp marks in my driveway, and my wife gives me dirty looks as if I'm doing it on purpose. At higher speeds and while towing I don't have a problem.



I was also wondering how the stock mopar rear disk conversion is working for those that have done it? Is it a bolt on conversion for SRW trucks? I may consider doing this mod later if it's not too big of a hassle.



Thanks for any input.

 

[KFroese]

the only thing i could suggest is pull the drums of to check everything over. get some emory paper and lightly sand the shoes and drums and throw it back together, and check the adjustment. also make sure the E brake fully release's



did the kit come with new drums? was there a "coating" on the inside of the drums?

 

[John]

The EGR Severe Service rear drum brake kit does not come with new drums. However, I'll bet EGR would sell you a set if you asked.

 

[KFroese]

the reason i asked was i've seen guys just slap on new drums with out cleaning off the factory coating they put on so they don't rust on the shelf. it makes the brakes wayyyyyy grabby.

 

[John]

I figured that was what you were thinking.

 

[Big E]

I used the original drums from my truck. I had them turned prior to the rebuild. The parking brake is not sticking. It does hold like a rock now. I'll probably pull the drums off when I get a chance and recheck my work and clean out any dust from the new shoes wearing in. I'm starting to think I should have used regular shoes and bought an e-brake instead.

 

[Joe Mc]

Long but worth it

Big E,



Sorry for the novel but, it really solved my problem and made the truck a joy to drive/stop once again.



Sounds like you are referring to the hopping situation I had w/my 99 (rear drums). Boy did I go thru some blood, sweat & tears, not to mention $$$, before I finally found out what to do. I had my drums cut to true them up to the new shoes "NG" (no good). I replaced the drums still NG, had new drums cut NG $$$$.



Sam P. is "The Brake Man"! Sam suggested fitting the shoes to the drums. Of course I never heard of this But, after thinking about what he said and what was happening the light bulb finally lit up. Only problem remained was how to do it myself. For the sake of not confusing anyone and protecting Sam P's good name he did not tell me to perform the following steps. It worked for me and I'm only trying to explain what I conjured up to fit the shoes to the drum and stop the god forsaken shaking.



Explain: If brake shoe arch doesn't match the diameter of the drums strange things happen. If the top and bottom of the shoe are the only part touching the drum a "heel-toe" situation takes place causing the shoes to "shake"/"grab alternating heel then toe of shoe" inside the drum, hence giving a hippity hoppity stopping experience of course this is only noticed below 25 - 20 mph. Sound familiar yet? Read on: likewise, if the center of the shoe is the only part touching the drum a similar situation occurs, usually only at lower speeds of 10 or less mph. Bet this is really hitting home about now.



Evaluating the situation: Plan this for at least 4 - 6 hours depending on work area set up/number of cold beverages . Set rear on stands, remove both wheels and drums. Do the following steps one side at a time to ensure you re-install all the brake hardware correctly - using other side as a reference when re-installing the one you are working on. Here goes - remove the shoes and place inside the drum as they would be if still on the truck. Go to a level work space and place one shoe outside the drum on the bench. Take the remaining one and raise it to the area on the drum where it normally rides, being sure to have toe, center & heel level on the wear line of the drum. Now, looking down from a top view of the drum as if you were the axle, notice if the heel & toe are touching the drum. Is there clearance in the middle of the shoe? Or, is the middle of the shoe touching and your clearance is heel & toe? I'm talking . 020" is too much clearance heel/toe. Clearance is to be @ heel & toe and the center of the shoe needs to touch the drum. I think Sam P. said optimal is . 012" - . 015" but not positive.



The fix:



If too much clearance is in center of shoe you need to bend the shoe frame to make it slightly slightly smaller to provide some clearance @ heel & toe and contact at the center shoe to drum. How to do this took the longest time to figure out utilizing the tools I had on hand. Find 2 "C" good size clamps, a 3/8" drive extension 4" long and feeler gages. The fun part is trying to keep the shoe in place on the drum while fitting all the tools to make the adjustment on the brake shoe frame, I recommend finding someone (who won't ask too many questions) to help hold things until you can locate clamps & extension on the drum/shoe. Place the extension at the top (or bottom) of the shoe frame, between the shoe & drum, using the brake material as a guide to help keep the extension in place. Place one end of the clamp in the center of the shoe frame and the screw end of the clamp outside the drum, tighten the clamp slowly and observe the center of the shoe moving toward the drum. It really works! Try not to go too far as removing clearance from the center of the shoe is easier than removing it heel/toe. Check clearances frequently until you dial it in.



If too much clearance is heel/toe (or if you bent the shoe to far trying to correct the center clearance) you need to bend the shoe frame to make it slightly larger. Place about a . 030" feeler gage between the middle of the shoe and the drum, clamp each end of the shoe frame to the drum, tightening the clamp screws equally until they touch the drum. Remove clamps, feeler gage and check heel & toe clearances. If the clearance is too tight re-do with thicker feeler gage(s) and keep checking/adjusting until desired clearance is obtained.



Finish the other shoe. Make sure you clean the brake plate pedestals (where the shoe frame contacts the brake plate), if there are grooves on the pedestals file flat. Then apply a thin coat of white grease to them before re-installing, clean the inside drum & shoe material.



Wasn't that fun? Only one more side to go! Don't get me wrong, this procedure is a RPITA (royal pain in the . . . ) but is worked for me and returned my truck to a pleasure to bring to a gentle slow stop Vs. being bounced all over the cab previously.



As you all probably can tell, I don't work for any repair shop or, represent anyone other than what I've figured out myself with a bit of guidance from the good old TDR. Since it worked for me I figured I'd share it with the rest of the gang. Just be careful and take your time, walk away for a few minutes if it gets frustrating.



I strongly recommend doing this even if/especially if you are installing "new" shoes. It's easier to do it when they're off than after you've installed them. :-laf



enjoy!

 

[Big E]

Joe,



Thanks for the tip. I'll check this out when I pull the drums off.

 

[kentdiesel]

There is one more way to insure the brake shoe fully contacts the Brake drum, it is called "Cam Grinding the Brake Shoe" Some older Brake Drum Lathes had the ability to do this. The way this works is the Brake Shoe is mounted next to a sanding disc and rotated in a arc the same as the Brake Drums Diameter. The sanding disc shapes the lining on the shoe to perfectly fit the diameter of the Brake Drum. This makes for a great set of Drum brakes with no "wear in" period. Ammco Brake Lathes had this "Cam Grinding" feature available as an option and I have used it on others but I don't remember the brand name. You don't see this on new brake lathes because the focus is now on disc brakes. If you can find a old garage that been in business for years they might have one of the old brake lathes that can Cam Grind Brake Shoes. The younger generation knows nothing about this.



Kent

 

[John]

Kent, ya beat me to it!



After reading Joe's lengthy but very informative post, I was just about to suggest "arcing" the brake shoes (if they even still do this).



Twenty-five to 30 years ago this procedure was commonplace, as every set of brake shoes came oversize. The drum(s) was/were turned and subsequently measured. That measurement was used to setup the arcing machine. The proper offset was "dialed in" and the shoes were arced as required for a precise fit.





It's funny, I can still remember hanging around my local NAPA dealer 30 years ago now...



standing by, watching the automotive machinist arc a set of (100%) asbestos ( ) brake shoes to size... no suction fan, no particle mask, nothing. Of course, that was well before the health risks of asbestos exposure were known.



Funny thing is, if you could even work with 100% asbestos (which I doubt), you'd have to wear a "moon suit" with an air tank or at the very least, outdoor supplied fresh air.



My how the world we live in has changed!

 

[kentdiesel]

Originally posted by John

Kent, ya beat me to it!



After reading Joe's lengthy but very informative post, I was just about to suggest "arcing" the brake shoes (if they even still do this).



Twenty-five to 30 years ago this procedure was commonplace, as every set of brake shoes came oversize. The drum(s) was/were turned and subsequently measured. That measurement was used to setup the arcing machine. The proper offset was "dialed in" and the shoes were arced as required for a precise fit.





It's funny, I can still remember hanging around my local NAPA dealer 30 years ago now...



standing by, watching the automotive machinist arc a set of (100%) asbestos ( ) brake shoes to size... no suction fan, no particle mask, nothing. Of course, that was well before the health risks of asbestos exposure were known.



Funny thing is, if you could even work with 100% asbestos (which I doubt), you'd have to wear a "moon suit" with an air tank or at the very least, outdoor supplied fresh air.



My how the world we live in has changed!

Well John, this could only mean one thing. . We are getting old!

 

[John]

LOL!

 

[Big E]

I pulled the drums off this morning. The trailing shoes are not contacting fully in the center 1/3 or so of the shoe. The leading shoes are contacting along the full length but not evenly across.



There was a lot of dust inside so I cleaned the shoes and drums out with brake cleaner. This solved the problem. My guess is that the dust buildup on the low points of the shoes is causing the grabbing problem. I assume that the problem will disappear once the shoes have worn in. If I have to clean them out again I will. I really didn't feel like pulling them apart again especially since the temp is supposed to be close to 100 today.



Next time I do a drum brake job I will check the fitment.



I was hoping to hear from someone that did the oem disk conversion. Anyone?... Anyone?... oh well.

 

[krs]

John, I'm gasping for breath today from a few years of working with just such a machine in just the way you describe. It was common and the arcing machine was as good at making asbestos dust as a router can make sawdust.



I'm not too sure I'd feel good about bending brake shoe 'frames', as I'd think about cracks developing later. Most shoes sold these days are pre-arced to the standard drum size and work acceptably in most instances with oversizes out to the limit cast into the drum. If I somehow found some shoes that were not arced (usually there's a tell-tale in that the ends of the friction material is cut at a steep angle for the last 1/4" or so), or if I had a vehicle that didn't respond well to the usual procedures I'd go find someone who still has an arcing machine. The last one I had anything to do with was a stand alone machine made for that purpose and equiped with a real pita of a dust containment system and capable of working out to 19" size. I last saw it in 1996 and it was still OSHA approved for use. A specialized brake shop would probably have one as it can be a jobsaver in problem situations.