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I was wondering guys , whats your front brake control turned to in your B models? Im running empty on a dry road and wondering whatto do? , forgive me if it sounds stupid ive never had one like this one in a truck before, Jay

post-2596-127333122155_thumb.jpg

Edited by jaysm35a2
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I was wondering guys , whats your front brake control turned to in your B models? Im running empty on a dry road and wondering whatto do? , forgive me if it sounds stupid ive never had one like this one in a truck before, Jay

P.S. it takes a long time to stop huh?

Edited by jaysm35a2

It cuts down the application pressure to the steer axle brakes when it's turned down. That's supposed to prevent front wheel lockup and loss of control when driving on slippery roads.

When on dry roads leave it all the way turned up for maximum braking.

"If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

Thats exactly what I was thinking, so ill crank her all the way over so I can finally stop the ol Dog within 40 acres.

:SMOKIE-LFT:

Hi Jay;

Hey,I noticed in your pic you have the Green/Chrome(?) :mack1: mud flaps on your truck. :thumb: How's the quality on 'em? I'm thinking of picking a set up for my ol' EH model,in Green,because it matches the paint.

Speed

:SMOKIE-RT:

"Remember-ANY Gun Control is Unconstitutional!"
<!--sizeo:3--><span style="font-size:12pt;line-height:100%"><!--/sizeo--><i><b>MACK-E Model Registry # 36</b></i><!--sizec--></span><!--/sizec-->

<a href="http://www.nvabatetravel.com/"target="_blank">http://www.nvabatetravel.com/</a>

Speed, I got them from a girl on ebay/Susan thats a great help. They are holding up pretty good, I havent noticed anything worn off them. I also have the quarter fender rubber flaps the same way and they are still looking good also. She has them in Mack red,Mack green , and your regular black. -Jay

Ive never seen that "block off plate" between your brake control valves in a b model before. It looks to have the same patina as the dash, what is it covering? Every b model ive ever seen has either had air valves there or nothing at all.

Paint?????

laffin

Packer

Yeah,okay,Packer-as I remember it,your E is kind of a RUST color,isn't it? ;) At least mine HAS a color...

"Remember-ANY Gun Control is Unconstitutional!"
<!--sizeo:3--><span style="font-size:12pt;line-height:100%"><!--/sizeo--><i><b>MACK-E Model Registry # 36</b></i><!--sizec--></span><!--/sizec-->

<a href="http://www.nvabatetravel.com/"target="_blank">http://www.nvabatetravel.com/</a>

Back to the question of the front brake control:

I have a flipper switch that reads Slippery/Dryroads.

I have seen a control valve like the one in the pictue!!

It was mounted on the floorboards of a 1957 B-63.

The purpose of THAT valve was to adjust applied air the the trailer brakes.

When running empty, the trailer brakes were tuned down so that the trailer brakes never locked up and skidded the tires.

It would be a big no-no now, but at the time, was used to keep the trailer tires round and with-out flat spots.

When loaded, the valve was turned back up and down the road you went!!

Packer

Keep a clutchin'

Would that be like the trolly brake I have on the steering column?

P.S. I dont have the flipper switch in the B model(just this one) but the R600 has one on top of the dash for wet/Dry roads.

Edited by jaysm35a2

No.

The valve on the column is for trailer brakes only.

Before engine brakes were invented, the prosess of going down hill was a whole differant world!!!

Gear WAY down and set about 5 pounds of air all the way around and ease down the hill.

(Here in the west, that could be several miles of 5-7% grade)

The only time the trailer brake was used was in case the tractor brakes were smoking and the trailer brakes were not.

Then you would use the trailer brakes only for a bit until the tractor brakes cooled down, or the stop a jackknife on slick, snowy roads.

The proportioning valve was only for running empty, and the foot valve was used in the normal way to stop the truck.

DOT would frown (and I do mean FROWN) on the use of one now.

However, if you find your way clear to part with it, send it to Wyoming!!!

I know a guy that could use it!!!

Packer

Keep a clutchin'

It cuts down the application pressure to the steer axle brakes when it's turned down. That's supposed to prevent front wheel lockup and loss of control when driving on slippery roads.

When on dry roads leave it all the way turned up for maximum braking.

Hi Herb, my A40 has the same control and if it is set on anything but all the way down when the truck is empty, the front brakes are very agressive with new shoes and fresh machined drums on the steer. When loaded and driving like one is supposed to, it stops fine on low, but stepped up to medium, or high, is much more agressive. I can't lock the tandems, (loaded) in a panic stop, but the steer will with little effort when turned up.

Rob

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

Hi Herb, my A40 has the same control and if it is set on anything but all the way down when the truck is empty, the front brakes are very agressive with new shoes and fresh machined drums on the steer. When loaded and driving like one is supposed to, it stops fine on low, but stepped up to medium, or high, is much more agressive. I can't lock the tandems, (loaded) in a panic stop, but the steer will with little effort when turned up.

Rob

Hi Rob;

It sounds to me like your rear axles aren't getting enough air and the front's getting too much. Sounds almost like it's working backwards.

Speed

"Remember-ANY Gun Control is Unconstitutional!"
<!--sizeo:3--><span style="font-size:12pt;line-height:100%"><!--/sizeo--><i><b>MACK-E Model Registry # 36</b></i><!--sizec--></span><!--/sizec-->

<a href="http://www.nvabatetravel.com/"target="_blank">http://www.nvabatetravel.com/</a>

Hi Rob;

It sounds to me like your rear axles aren't getting enough air and the front's getting too much. Sounds almost like it's working backwards.

Speed

All axles get line pressure, (reservoir) when selected on high as I've checked with a gauge. I don't know anything about condition of the linings on the rear other than they all work and are adjusted properly, never had them apart but I suspect they are glazed/shot. They are very old from what I can see through the backing plates. I had the fronts relined cause they were down to the rivets.

Rob

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

All axles get line pressure, (reservoir) when selected on high as I've checked with a gauge. I don't know anything about condition of the linings on the rear other than they all work and are adjusted properly, never had them apart but I suspect they are glazed/shot. They are very old from what I can see through the backing plates. I had the fronts relined cause they were down to the rivets.

Rob

I'd bet that the front brakes are working properly, since they're new, and as you said, the rear brakes are shot so they're not doing their share.

"If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

Back to the question of the front brake control:

I have a flipper switch that reads Slippery/Dryroads.

I have seen a control valve like the one in the pictue!!

It was mounted on the floorboards of a 1957 B-63.

The purpose of THAT valve was to adjust applied air the the trailer brakes.

When running empty, the trailer brakes were tuned down so that the trailer brakes never locked up and skidded the tires.

It would be a big no-no now, but at the time, was used to keep the trailer tires round and with-out flat spots.

When loaded, the valve was turned back up and down the road you went!!

Packer

If you look at the pic in Jay's original post, the word "Front" is stamped on the control knob.

.

"If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

Would that be like the trolly brake I have on the steering column?

P.S. I dont have the flipper switch in the B model(just this one) but the R600 has one on top of the dash for wet/Dry roads.

The trolley valve is used to apply the trailer service brakes independent of the tractor service brakes.

On straight trucks not set up to pull a trailer, the trolley valve applies the drive axle service brakes.

That "wet/dry" flipper cuts down the pressure to the steer axle brakes, same as that control in your B model, just that it's not variable like the older type.

.

"If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

Ive never seen that "block off plate" between your brake control valves in a b model before. It looks to have the same patina as the dash, what is it covering? Every b model ive ever seen has either had air valves there or nothing at all.

My b61 has the same block off plate and hole to each side. The valve to limit front brakes was on a hang below the dash added bracket. It looks like a radio would fit in there, and it does. I have a am radio from a early sixties gm car that fits like it was made for it. Sence my cab came from a firetruck (b-85f)I assumed it was for a radio of some sort. It has the same block off plate and some chrome buttons in the holes on the left and right of the block off plate. I have never seen another like it till now..... I thought I was special....

Fred

15 gears...no waiting!

that rectangle plate you are referring to is a Radio delete plate that was in all b models from 53-55. also the choke, throttle and windshield wiper knobs were higher on the dash from 53-55. that is also when that type of front wheel brake control valve was used under the dash with the knob. after 55 Mack got rid of the radio delete option and moved the ash tray and choke throttle down on the dash and also started using the flipper style levers for front wheel brakes and truck tractor protection valves. the reason no one has seen them is that there arent many 53-55 b models left anymore.

post-6-0-64947600-1408238925_thumb.jpg

that rectangle plate you are referring to is a Radio delete plate that was in all b models from 53-55. also the choke, throttle and windshield wiper knobs were higher on the dash from 53-55. that is also when that type of front wheel brake control valve was used under the dash with the knob. after 55 Mack got rid of the radio delete option and moved the ash tray and choke throttle down on the dash and also started using the flipper style levers for front wheel brakes and truck tractor protection valves. the reason no one has seen them is that there arent many 53-55 b models left anymore.

The firetruck was built in 57, but I didn't know that there was a radio option on b-models. Goes to show you... I can learn something new everyday! Thanks

Fred

15 gears...no waiting!

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