Drum brake question

J

Joe Craven

New member
We just finished our 2nd season race at Laguna Seca and I had a blast in the Capri. I found out that Laguna is a heavy braking track I had a couple of braking problems. I installed some brake cooling ducts after practice and that seemed to fix my front heating problem. My odd problem is that I seemed to lose rear brakes in the Qualify and race. I am running Porterfield R4 compound front and rear and I was getting extreme wear at both ends. What I think is happening is that the rear brake pads are wearing so much that the brakes get too much play to work effectively. By the end of the race, I was locking both fronts. Brakes were really strong in the beginning and that was where I was gaining on the BMWs.

Has anyone ever experienced a similar problem with rear drums. I'm wondering if I should try one of those residual rear brake pressure things. Here is a link to the Summit site.
http://store.summitracing.com/partdetail.a...IL%2D260%2D1876

They have them in 2 and 10 pound varieties. I'm wondering if I can rig up the automatic adjustment thing to work or perhaps I should just go with more wear resistant lining material.


BTW, I took the ITB lead at my weakest track 25 minutes into the 30 minute race. On the last lap, I went wide in the last turn (#11) due to front brake lock and I ended up spinning. I ended up in 3rd position.

#37 ITB Capri
 
Joe--I do not know much about Capris, but if you run Enduros, I would re-hook up all the parts for the adjusters.

Sounds like your pedal height is going away.

The other idea is a proprtioning valve to reduce the load on the rears a bit. Also sounds like you are having too much rear shoe wear.
 
Hey Joe, I'm having this wear problem in a 30 minute race.

I've worked hard to get my rear brakes to work, I'd hate to proportion them so they did less work.

My brakes were working great. I was out braking at least one of the BMW 2002s, pulling 1/2 car length every time we headed into turn 11.

Newsflash. I just called Porterfield brakes and told them what is happening. They said that some of their customers wear through a new set of pads in a typical Laguna Seca race. I guess I'm not going fast enough!

Anybody know where I can get custom brake shoe material with stuff more durable than Porterfield R4?

#37 ITB Capri
 
Joe,

I saw your pass in the corkscrew, (I was working Turn 8A Comm). I was cheering you on; sorry you didn't hang on to first place. But it shows you can give the BMW's something to think about besides another BMW.

Barry ITB # 42
 
Don't know if this helps...

My father raced a Showroom Stock Capri II in the late 70's quite successfully (5th at the 77 runoffs).

I suspect that the Capri II is similar brake wise to the Capri I's. (Girling Calipers up front/drums in the rear?)

In the good old days of Showroom Stock OEM pads, the front brakes would last an entire National weekend (Practice/qualifying/race) at Blackhawk (THE toughest track in the country on the brakes!!!). The braking capacity never varied during the race i,e, not much pad left but what was their still worked.

We never had a problem with the rears. They would last half a season or so. I would suggest that you confirm all of the mechanicals are in good working order at the rear i.e. adjusters clean and functional, drums trued, etc.
 
Barry, I thought that was you working in 8! It was a bit difficult to tell while I was racing trying to brake, turn, accelerate etc. You must have seen the earlier tap between our cars when Tom, I and that Datsun went 3 wide into the corkscrew. I think that Datsun was trying to get out of the way of these crazy ITB cars. I was consistently getting a better drive out of 6 but not enough to pass before the corkscrew. I wasn't as fast as the BMWs in the corkscrew, often losing 1/2 car length which I had to gain elsewhere. Good news is that I have lots of room to improve there.

Greg, brakes are almost identical between the two models. I used to run stock compound brakes shoes in the rear and those used to last 1/2 season too. They just didn't seem to have enough bite and I eventually realized how deficient my Capri brakes were after I started racing a VW. The Porterfield shoes in the rear really improved my Capri's ability to brake. I've run the car at Sears Point and Thunderhill with the new brakes and my Capri stops almost as well as my VW GTI. My rear brakes are so powerful that I have to use a proportioning valve to cut back on the pressure to them. I only ran at Laguna Seca once several years ago and I wasn't fast enough to really work out the brakes. This time at LS however, it seems that I'm wearing out at least 25% of the full lining everytime I do a 20 to 30 minute session.

I think I'm going to call Carbotech and see if they have a lining that will wear slower than the Porterfield R4

#37 ITB Capri
 
Joe,

For what it is worth, I have tried Porterfields and Carbotech. No comparison, the Carbotech Blue compound is by far a superior pad. It is the same compound as Hawk Blues. Here in Cen-Div, I tried a set at Blackhawk and they sucked!!! They were very inconsistant. If I backed off for a lap to cool them down they would come back for a few laps and then go away again. When I pushed them really hard I actually bent the backing plates and wound up with 'U' shaped pads!!! I put a set of Carbotechs in and they work great from start to finish and last 6-8 race weekends! A fellow Honda competitor and friend of mine also tried a set of Porterfields and he didn't like them either. He then threw a set of PFC's (which we can't get anymore for our Hondas) and couldn't believe the difference.

Good luck with the Carbotechs! I think you will be happy with them. They are slightly more aggressive on the rotors and drums, but in these days, most people treat brake rotors as consummables since they are cheaper than the pads in some cases. (At least they are for VW's and Hondas). You may find out that your brake balance is restored if you run 'real' pads up front instead of the Porterfields as well. Follow the bedding procedure
 
Greg, I've experienced the same thing with the Porterfields many years back at Pomona Raceway down in SoCal while racing a 1980 Datsun 510 Series II ITB car. I was amazed to see the pads wrapped around the piston in the caliper.

Drums are a bit pricey but listed at $70 each. I guess I'll have to live with the wear.

Thanks
 
Back in the old Champion Spark Plug Challange in a Pinto which had rear drums we used Velvetouch full metallics and had no problem. They would even work when the rear axel seals would leak oil on them. The last place I had them made was Racer Walsh who got them from Rochester Brake and Clutch I think. Your drums might wear but not the shoes. The front pads were TIG welded to the backing plates, the rear shoes were riveted and bonded. Thats real metallic!
 
Hi Joe, Glenn again, Poterfields we tried them they cracked the 1st weekend i used tham at holtville (flat airport track) only three faily hard braking zones!!! We beded them in sat nite and ran them in sudays race, the old mkd90 bendix never cracked or broke down!!! Good luck hunting Rabbits and 2002s also if u need a good price for those drums let me know!!! LATER GLENN
 
Glenn,

How do the Hawk Blues compare to the old MKD90's ??? I've generally had very good luck with the MKD90s on my Pinto

Barry
 
Barry, Hello fellow pinto racer, the mkd90 were always very consiste, but I was always at Willow Springs, Holtville, ELIVS, or RIVERSIDE (R.I.P.) so none were really hard on brakes like Laguna. i have never tried the blue Hawks, but tried other street met. pads, Barry what year is your Pinto? Glenn
 
Glenn,

Its a 1974, with the 2.3L. I've only run Sears Point Opps Infineon, laguna and thunderhill. I'm coming back after a ten year lapse, tring to remember how to drive.

Barry
 
Alert - Thread Hijack ---***********

Barry, didn't the 74 Pinto come with both the 2 liter and the 2.3 liter?

I'll look in the ITCS.

Yep, put in a 2 liter and remove 260 pounds - WOW!

Comparing carbed motors, 2 liter makes more power than 2.3 and the weight difference could make the Pinto a front runner.

#37 ITB Capri, however Pinto looks good at 70#s less than Capri.
 
Joe,

The car weights 2343 without driver, and I don't know where I can clean/remove things to lower the weight. the only weight loss is in the driver. If I do lose 100 lbs as suggested by my doctor it would bring the car close to the minimum weight.

I run the 2.3L as it seems to pull as well as the 2.0L and has more potential HP as I learn its secrets.

Barry

PS I ran with Mike Stevens and the Capri at Fremont Dragstrip, and we were within 5 ft at the Quarter mile mark.
 
Barry, I too am getting back into the racing duties, tested last month at Holtville, and looking fowards to the next event after about 6 and 1/2 ytear lay off from racing the pinto (it is a 1979 tank) thanks Glenn
 
This is in reply to the comment of putting the adjusters on for the rear brakes. I have only seen adjusters work while going in reverse never going forward. Check into this as it has been quite some time (early 80's) since I turned a wrench on the old Capri. If the star wheel is spinning during the race the adjuster will stop the reverse rotation. Good luck

BTW I would love to drive Laguna Seca. I only get to enjoy it by way of video games on the East Coast. When I hit lotto I will have to come out and try it.
 
Do you know anyone north of the border? You can still buy "Metal Master" pads and shoes up there. I ran these on a 80 Pinto IT-B and lost a rear seal. Fill'd up the drum with oil and the lap times never changed. They would wear like iron, yet were easy on the rotors. Now I run stock on the rear and it doesn't seem to matter. Realy the rear brakes should only keep you going in a straght line and not be doing so much work that they go away. Make sure you drill out the breather tube to .125 id on the rear end and you'll not pop any seals. Dick
 
Perhaps, I have some old/new metal master front pads in my cabinet somewhere. I will be running the Capri at Laguna Seca the end of June and hopefully my motor will stay together. I pounded a rod bearing at Thunderhill in practice so I had to retire the Ford. I brought out my ITB VW, great car but it just is not developed enough.

My goal is to get the brakes on each end working as best as they can. With stock pads, the rears didnt do much so they worked as you described. I have a new rear set made by Carbotech which should wear longer than the Porterfields. My brakes worked absolutely great the last time I ran on the Porterfields, it was the lining wear that caused my brakes to get out of adjustment.

I am optimistic that these brakes will work, just not about my motor. I am worried that my rod end is a bit out of round, but I didn:t have enough time to properly repair the motor so I just through a new set of rod bearings in it. I am out of the country for a couple of weeks, cutting my vacation short to return the night before my race weekend.

37 ITB Capri again.
 
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