What wonderous truck manufacturer would do something so intelligent?

On P-Series vans made by Workhorse (Satan) the hole on the rear rims is typically like 2"s across, you can barely get two fingers in there and the air chuck.

Other trucks are much better, I agree. I guess I judge everything by the standards of workhorse trucks, endless pains in the a$$ that you can never fully get rid of!

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This post brought to you by Carl's Jr.

SATAN! I love it! My 12T 90 NV car hauler (I refuse to call it a ford) has 2"x4" oval chuck holes...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

We're talking "apples to oranges" here.

On a medium-duty, you have juice brakes, air over hydraulic, and pure air. Disk, drum, and combination. On these trucks and buses, 60-70% of the braking is on the drive axle, which is the opposite of a passenger car. They have a very large swept area, and the larger ones have relatively slow-turning wheels so the speed that the friction material sees is low (504revs/mile IIRC on a big-rig with 11Rx22.5 rubber).

Many have drums on the drive axle, just because they couldn't get the swept area on a disk. When drums heat up, they grow in size, and eventually the S-cam can't apply enough pressure or it is only at one end of the shoe, which is bad (BTDT). Disks don't run out of travel, which makes them inherently safer, but the temperature of the friction material if too high starts to reduce the coefficient of friction, meaning it needs more pressure to brake, and that too can eventually become a problem.

On a truck, the rule is that you never rely on brakes to hold speed, only engine braking/retarder. If your engine can't hold your speed you need to slow down and gear down until it does.

The brakes on a car, being 4 disks on most of our Mercedes, aren't as prone to fading as drum brakes and are usually the same ones that are supplied in Germany where it can legally be driven much harder/faster. I've not yet driven a Mercedes car that didn't originally have excellent brakes for its power and weight.

The cooling effect of air escaping from under the car through the wheels becomes important when driving on a mountain as mentioned, or hauling / carrying a load. Also if driving hard enough to brake hard and then accelerate to brake again (and again). If the OP is planning on any of these, I'd say that better cooling from removing these shields is a good idea as they almost certainly must reduce airflow significantly compared to the centrifugal air-pump design of the original 15-hole wheels. It also will decrease (however slightly) the heat transferred from the rotor/hub into the alloy wheel.

If normal driving, I'd not worry too much about brake cooling.

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Gone to the dark side

- Jeff

I generally agree.

One side note is the hotter your rotors get, the more likely you are to warp them or transfer pad material to them after you stop.

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1981 Mercedes 300TD, 1994 Honda Civic Del Sol
http://mefi.us/images/fuelly/smallsig-us/67195.pnghttp://mefi.us/images/fuelly/smallsig-us/103885.png

With 205,000 miles on it the dust shields on my 85 300SD have never warped a rotor or caused any brake issue. I drive up and down the mountains in PA as well as VA an WVA. I tend to drive in a somewhat spirited manner. No issues.
I admit I like the look of the rotors through the wheel openings but this way they stay cleaner. Just my 2cents.
Alan

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92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )

for a new W123 owner.

.

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ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

I like the idea of clean wheels but have not had good luck long term with them. they tend to get bent and I discard them.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Once you've experienced brake fluid boiling (Seized rear caliper on my '84 TD & seized rear parking-brake cable on my '98 Altima) you're REALLY overcome with a strong desire to never experience it again!

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DrDKW