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View Full Version : Air Brakes Freezing -How To Prevent??



swampdog
12-11-2008, 09:37 AM
Can anyone give me some tips to keep the air brakes from freezing on the Cat 966C?

The valve under the left brake pedal has frozen up a couple of times, due to moisture that freezes. That releases all the air from the system, and the brakes lock on. Then I have to back off the brakes and thaw out the valve. I drain all the air from the tank after use but that doesn't seem to be enough to prevent the freezing.

I don't see any place to add alcohol or brake anti-freeze in the system. I've heard that alchohol is not good for the seals and other parts in the air system. Is there a safe product to use, and where would one add it?

Thanks for your help!

curly
12-11-2008, 11:03 AM
There are products out there to dry air brakes, used em every winter when driving truck. I'm not sure where you would add it though on a loader.

DR RPM
12-11-2008, 11:21 AM
Add a brake line anti-freeze sniffer inline from the compressor and the tank, most truck parts places will carry it. :bash

swampdog
12-11-2008, 03:15 PM
It would be nice to have an automatic injection system; a Mack truck I once owned had a brake antifreeze evaporator container.

In the meantime, is there any good way to add a little anti-freeze to the air tank or into the lines? If so, where is a good spot to add it and how much would one add? Thanks.

51kw
12-11-2008, 09:02 PM
We have 6 of them at work. We pull the plug out of the side of the air tank and add about a pint of airbrake deicer. Drain the tank again in the spring. You can leave it in all winter, We dont seem to have any seal troubles.

Northart
12-12-2008, 12:46 AM
Hello Swampdog,

You need to set up a Tanner Gas System. :)

The Model T-90 is what is used commonly up here, on construction equipment. It is bolted to the outside of the engine cover somewhere. Works great ! :)

Here's a link to it. Read everything about it there.


http://www.tannersystems.com/Comdspnsrs.html

Northart
12-12-2008, 01:59 AM
Hello Swampdog,

They come in various sizes , for different equipment.

Here's a picture of one mounted on a Cat 14H grader .

Northart
12-12-2008, 06:40 AM
The above picture is not the Tanner Gas System, it is a Desiccant Air Dryer System on the Cat 14H .

bolt thrower
12-12-2008, 10:03 AM
Swamp Dog, I think an air dryer, like the one shown on the grader pic is the answer to your problem. All newer equipment with air brakes come with a dryer installed and if it is working correctly, the system will never freeze. The idea is to catch and remove the humidity from the compressed air as it leaves the compressor, and not let it get into the system where it can freeze. Putting alcohol in the system is treating the symptom, but not the cause, and yes it may be bad for the seals. A custom install on your 966C wouldn't be too dificult.

swampdog
12-12-2008, 05:37 PM
Adding an air dryer does sound like a good idea. I'm not planning to use the loader much before spring, but it might be worth it anyway.

I don't know much about the air dryers. The one in the photo, a dessicant dryer, looks as if it needs no electical hookup. Some others that I have seen need a connection to the electrical system and seem to work by warming and drying the air.

I'm wondering about the pros and cons of the two designs. Is it necessary to change the dessicant material or filters in the dessicant dryers? What kind of cost might be involved in replacing those parts?

surfer-joe
12-12-2008, 08:15 PM
Northart has it. Airdriers work well in less frigid climes, but for heavy duty cold there is absolutely nothing that beats a Tanner Gas injection system. It's not fool proof, they have to be maintained. But if you want to keep going with little to no trouble in deep freezing cold, they are the only way.

Here is their website: www.tannersystems.com

By the way, do NOT install one of these systems ahead of an air drier. It has to go between the drier and the wet receiver.

You can set up an account over the phone and order direct, or they have a few dealers scattered around. More up north you know than the south and west.

Tell them Joe sent you!

Randy Krieg
12-13-2008, 02:13 AM
Swampdog
We use both; a dryer and a sniffer. The first generation H Series MG (NothernArts Picture) had the same dryer as the G Series and yes about once a year you have to change the desiccant. This dryer was used on numerous Cat products fof years. They sell a great rebuild kit; it has the screens, O-Rings, Desiccant, etc. etc. If you let your engine oil change go too long then youíll be doing it sooner! Long before the engine oil starts going past the engine rings it starts going past the compressor rings. As soon as that oil gets in the desiccant itís useless. The second generation H Series (Tier III) uses an airdryer with a spin on replaceable filter. Way cooler and way easier, but way more expensive. (at first)

On the electrical side; the heater is for the expello valve. The expello valve, which is mounted on the air dryer, is tripped by the air governor. This dumps the accumulated moister out in to the atmosphere. The heater is generally tied directly to the key and keeps the expello valve from freezing. I replace the heater every time I rebuild one of these dryers, even if itís still working (donít ask how I test them).

And yes Surfer Joe is right; make sure the sniffer (we use both Haldex/Midland & Tanner Gas) is down stream from the dryer (between the dryer and the tank).

In regards to alcohol ruining seals; that is correct! Alcohol will eat up Viton. ďTanner GasĒ is not straight Alcohol; it is formulated specifically for this purpose.

Remember alcohol absorbs moister, so you still need to DRAIN YOUR TANKS! It does not make the moister disappear; it just prevents it from freezing, provided you have enough.

Time for bed!
Randy

Komatsu 150
12-13-2008, 09:23 AM
[QUOTE=Randy Krieg;117325]Swampdog
The heater is generally tied directly to the key and keeps the expello valve from freezing. I replace the heater every time I rebuild one of these dryers, even if itís still working (donít ask how I test them).

I thought they had a built in thermostat to turn on the heater when cold. Is that wrong?

Randy Krieg
12-13-2008, 10:19 AM
Komatsu 150
I really don't know in regards to other brands of machinery or even the later model Cats. You could be right about that. I know on the earlier models that I have worked on they were energized as soon as the key was turned on. So many of the new products are going all hydraulic so non of this applies, but now you have my curiosity up in regards to the newer dryers. Our shop is installing airsystems on our 730s since some are converted to tractors and tow trailers with air brakes. I'll ask one of the mechanics about this today.

Have a great day..........Randy

dirtpig
12-13-2008, 09:31 PM
Go to a good truck shop and get a Bendix AD9 dryer for about $200 install and most of your trouble will disappear. The sniffer would be a help in climes more severe than where I want to be.

swampdog
12-14-2008, 10:44 AM
I looked around and haven't found the Tanner evaporator in this area. What is available is a Haldex Midland A72420. It holds about one litre of alcohol/lubricant mixture. It seems to be much the same thing as the Tanner unit, so I'll probably go with the Haldex Midland evaporator. Does anyone know if the Haldex Midland units are OK? For now, I'll probably just try the evaporator and hold off on the dryer.

The instructions say to mount the evaporator about 8 to 10 feet from the compressor, and before the air tank. The most convenient place to mount this would be below the right side engine cover, which would only be about two feet from the compressor. Can anyone see any problems resulting from that location?

Northart
12-14-2008, 01:01 PM
Hello Swampdog,

Far as I remember, the Tanner Gas Unit was mounted on the left side, or same side as you mount the machine. , by the side radiator cowling, under, the rear light bracket.

Not on the engine access covers.

Wish I had a picture of one, mounted. :( 8'-10' away ??? is not practical . :beatsme

The Caterpillar Desiccant air dryer is a Aerofiner 2, p/n 8V9101 made for many applications. Has a refill canister.

As I inquired from the Cat Dealer, they said there was no original air dryer, for the Cat 966C . Just retrofits.

Hope this helps.

Randy Krieg
12-14-2008, 02:05 PM
Gentlemen
It's 8-10 feet of airline that is required between the compressor and evaporator/sniffer. The air coming out of the compressor can get extremely hot. Thats why they use the Stainless steel braided line out of the compressor. On our 14 and 160H I have the Midland unit mounted in the engine compartment about 18" away from the compressor, but the airline comes out of the compressor goes all the way back to the dryer mounted at the back of the machine then exits the dryer and goes back up to the evaporator/sniffer, giving me the required 8 feet of line. I like mounting it in the engine compartment so it stays clean since you have to service it often. That way dirt doesn't get in it when you remove the valve to add Tannergas. It's close to where the mechanics check the oil so they remember to service it too.

Komatsu 150; I talked with our mechanic regarding the heaters on the new Bendix dryer. He said the heater is optional, but the way they are wired is hot all the time (when the key is on). There may be something internally that shuts it on and off depending on temperature. I'm still doing some more reading on this when I get time because I did find an article that states the new buses and trucks work that way. It just doesn't say in the article if it's something on the truck or something in the dryer controlling it.

Randy

Northart
12-14-2008, 10:49 PM
Ha, I surfed the net, found this picture on Machinery Trader, Cat 966C with an air dryer.:)

Looks like there is options, for various schemes as outlined by others.

swampdog
12-14-2008, 11:27 PM
Northart, that is a nice looking 966C that you found. The old Cat loaders do have nice lines.

That does look like a good location to install an air dryer. But to begin with, I'm planning on only installing the Haldex Midland alcohol/lubricant injector and holding off on the dryer. Are you suggesting that spot next to the air tank as a good place for the Haldex Midland unit? I haven't been able to confirm whether a direct line runs from the compressor to the air tank; the lines are hard to trace. If it is a direct line, that spot might not be much more than 8 to 10 feet from the compressor.

Sparffo
12-15-2008, 12:31 AM
The instructions say to mount the evaporator about 8 to 10 feet from the compressor, and before the air tank. The most convenient place to mount this would be below the right side engine cover, which would only be about two feet from the compressor. Can anyone see any problems resulting from that location?

if you mount the alcohol unit to close to the compressor, it will melt, burn or explode! thrust me, i live in Finland! :D we REALLY need stuff like that to get our airbrake things to move in the cold winter:beatsme and i really hate it...

on our Volvo FL10 truck we had problems with a line that came out of the air dryer, it melted after 3hours operating. even lines that are suposed to hold 10 bars at 110§c melted:eek:
the only way we got it working was to add a cooler coil in front of the dryer, the old owner had taken it away...
we made the cooler coil out of hydraulic tube (thin metall type) and made a spring of about 5metres of line, the spring was the size of a airfilter for the truck.

Northart
12-15-2008, 01:22 AM
Hello Swampdog,

Now, don't take me as an expert on this, I'm just relaying information from what I know.

The Tanner Gas units that I was familiar with, were mounted by the rear tail light bracket. As I show by the arrow in attached picture.

I'm also learning about other products, here, that I never knew existed .

Sounds like you can, coil up the hose , so you get 8'-10' of linear distance. Maybe someone will clarify that .

Hope this helps.

Komatsu 150
12-16-2008, 09:12 AM
Gentlemen
It's 8-10 feet of airline that is required between the compressor and evaporator/sniffer. The air coming out of the compressor can get extremely hot. Thats why they use the Stainless steel braided line out of the compressor. On our 14 and 160H I have the Midland unit mounted in the engine compartment about 18" away from the compressor, but the airline comes out of the compressor goes all the way back to the dryer mounted at the back of the machine then exits the dryer and goes back up to the evaporator/sniffer, giving me the required 8 feet of line. I like mounting it in the engine compartment so it stays clean since you have to service it often. That way dirt doesn't get in it when you remove the valve to add Tannergas. It's close to where the mechanics check the oil so they remember to service it too.

Komatsu 150; I talked with our mechanic regarding the heaters on the new Bendix dryer. He said the heater is optional, but the way they are wired is hot all the time (when the key is on). There may be something internally that shuts it on and off depending on temperature. I'm still doing some more reading on this when I get time because I did find an article that states the new buses and trucks work that way. It just doesn't say in the article if it's something on the truck or something in the dryer controlling it.

Randy

I was curious enough to look up the service info for the Bendix AD9. There is a thermostat that is part of the purge valve and heater, which is all replaced in one lump. Suppposed to turn the heater on at 40 deg. F.

onearmedbandit
04-16-2009, 06:02 AM
Can anyone give me some tips to keep the air brakes from freezing on the Cat 966C?

The valve under the left brake pedal has frozen up a couple of times, due to moisture that freezes. That releases all the air from the system, and the brakes lock on. Then I have to back off the brakes and thaw out the valve. I drain all the air from the tank after use but that doesn't seem to be enough to prevent the freezing.

I don't see any place to add alcohol or brake anti-freeze in the system. I've heard that alchohol is not good for the seals and other parts in the air system. Is there a safe product to use, and where would one add it?

Thanks for your help!
hi the air system should be drain of moisture every time that the shovel is used and we use methanol as an antifreeze in the brake system which works quite well
regards onearmedbandit