Changing Antifreeze

[dale farley]

I started draining my antifreeze this afternoon in preparation to switching to Extended Life. The Prevost manual says the system holds 24 gallons. I assumed the Webasto would hold a couple gallons more.

I have drained all 3 of the drain valves on the engine and lines, removed the plug from the bottom of the radiator, disconnected hoses from the Webasto and the heater lines, and I still have only 18 gallons of fluid. I opened the heater valve to let the heater lines drain, and that didn't seem to work, so I removed the lines in several places and that caused about another gallon to drain out the rear of the bus.

I have collected all I could so I would know how much I have drained. I don't know where the rest of the antifreeze can be. I placed 4" ramps under the front tires and lowered the rear of the bus to assist in the draining, but I don't see where I am going to get another 5 or more gallons. When I haved drained all I can, I intend to flush the system a couple times by filling with water and draining again after I run the bus until the thermostat opens.

Any suggestions as to how I can get any more antifreeze out of the bus? Has anyone else done this before?

[Jon Wehrenberg]

Dale, This is solely conjecture, but is it possible Prevost comes up with that quantity based on the bus air heat exchangers? I have gotten about 18 gallons out of mine, but that was when I was using and replacing the DD antifreeze. I have never made a substantial effort to drain every drop. Both buses, the 87 and this one seemed to drain about the same amount so I never chased what may have remained. In August I am switching to EC-1 so I have a real interest in finding where the extra coolant is hiding.

[ajducote]

When I had my antifreeze changed to long life, the mechanic disconnected both hoses in the engine compartment that go to the drivers heater. He then hooked a garden hose to one of the pipes and flushed it out until it ran clean from the second pipe. This completely flushed that whole heater loop. Then drained as much as possible by raising the front of the bus. He also turned on the "heat exchanger" switch for the AuqaHot and ran clean water thru that loop to flush it out. I don't know how much total old antifreeze was drained, but he went thru a lot of trouble to drain and flush as much as possible.

[truk4u]

Dale,

Assuming your going to buy your coolant at NAPA, please give me the NAPA part number when you make your purchase.

[dale farley]

Tom, I am changing to EC-1, and I got it at NAPA. I'm using the Zerex (P# ZXED-1 Concentrate). They also have the 50/50. I bought gallons of distilled water from Wal Mart to mix with it. Prevost says use distilled water. The antifreeze at NAPA is $16.72 plus tax. It was a little over $15 in January when oil was a little cheaper.

Jon, I think you may be right about Prevost's quantity being based on the bus air heat exchangers. I know the last time I changed the coolant (2 years ago), I just drained everything I could without disconnecting any lines, and I got a little over 16 gallons. This time, I poured 5 gallons of measured water in a 5 gallon bucket, marked where it came to in the bucket, drained it in the marked buckets, and allowed a little for spills, so I feel pretty confident about my quantity. When I had less than 5 gallons in the bucket, I poured it back in the gallon container to get an accurate measurement.

The worst problem I've had so far was removing the drain plug from the radiator. Because of its location and 5/16" square head, it is hard to get a grip on it and make it turn. It is brass. I used every socket, wrench and special tool I had to get it off. I heated it a little and gave up a couple times! I finally resorted to vice grips and was able to get it out, but I have to replace it with a new one before I reinstall it.

One thing I just noticed about the new software we are using, it is nice to be able to see the previous posts while posting a reply. We couldn't do that with the old software. A kudo for Jim Skiff.

[dale farley]

I was tied up a good portion of the day, but I did get time to drain and flush the system two times. The first time I filled and drained it today, there was still a significant amount of antifreeze and the solution was light green when it drained. The second time I did it there was no visible signs of antifreeze, and the solution was just a little yellow looking. I discovered yesterday that there is a 1" brass plug in the heating system that I can easily access when I lower my front bumper. When I remove that plug, it lets the heater lines drain quite freely. When I removed this plug after the second run today, the water in the heater lines was almost perfectly clear. Each time I filled, I let the engine warm up in the yard then drove a few miles with the Webasto running, the circulation pump engaged and the dash heater turned on. I was also running my OTR air and my dash air to neutralize some of the heat inside the bus and to help the engine warm up faster.

Just to be sure I have all the old antifreeze out of the system, I intend to attempt to flush water through the Webasto tomorrow, refill the system and take another short drive before draining the 4th time and refilling with the antifreeze. I was pleasantly surprised to see that the old antifreeze which was two years old, looked like new when I drained it out yesterday. I was also pleased that NAPA had the drain plug (that I messed up while removing) from the bottom of the radiator and a new radiator cap to fit the fill tank. They also had the drain cocks. One of mine was hard to turn, so I replaced it. In retrospect, I should have replaced all three of them. The brass radiator plug was $1.47, and the brass drain cocks are $2.47. I put lithium grease on the threads of the other drain cocks so hopefully, they will continue to turn easily.

[garyde]

When I had my anti freeze replaced in October, prior to Oklahoma Rally, I asked the Detroit Deisel Manager about the extended life anti freeze. He recommended against it. There is some information out there that it could be detrimental to your engine.

[dale farley]

I called Detroit Diesel World Headquarters and spoke to a Technician/Engineer. He said if an antifreeze meets the DD spec (7SE298) there should be no problem using it in any of the engines that have that spec. Naturally, they prefer you use their brand antifreeze. There are some marine engines that require a different spec and some antifreeze that is suitable for road use is not suitable for all marine use. He said he was not aware of any DD dealers telling customers that they shouldn't be using an EC-1 Extended Life antifreeze in their engines. He said he has never heard of any engine damage attributed to using an antifreeze that meets the specs.

For anyone interested in making the switch to an Extended Life antifreeze, this is the short version of what I did.

1. Shorted the sensor on the fill tank.
2. Opened all three drain cocks on the left side of the engine and removed the drain plug from radiator. Drained 18 gallons.
3. Removed the large drain plug behind fromt bumper and drained the heater lines. The lines drain through the drain cocks in rear of the bus, but the plug lets air in and allows fluid to drain. Without removing the plug, all the fluid will not drain from the heater lines.
4. Filled with clear water, drove about 10 miles, with Webasto running, Circulation pump on and dash heater on. (See note below about Webasto.)
5. Repeated steps 2 - 4 above four more times. The 2nd drain was still loaded with antifreeze. The 3rd was significantly less, but still very visible. The 4th lost all smell of antifreeze. The 5th was the clearest. I actually drained mine 6 times, but I could tell no difference between 5 and 6. Four times would have probably been minimally sufficient.

Refill
6. Closed all valves and installed the drain plug in bottom of radiator. Replaced old filter with new "non charged" filter. Installed 14 gallons of 50/50 mix and the reservoir was full.
7. Started engine and ran for 30 seconds, then shut off. Removed drain plug (behind front bumper) for heater lines and a little over a gallon of clear water ran out before I started seeing the antifreeze.
8. Started engine again and let run until warm. Added one gallon of 100% antifreeze and 2 more gallons of the 50/50 mixture. Shut engine down once it warmed up sufficiently.
9. When engine cooled, I added the last gallon of 50/50 which made 18 total.
10. Checked all drain cocks and drain plugs to make sure they were tight and no leaks. Removed short from sensor and connected to fill reservoir.

Webasto - On CC, we have 2 switches for the Webasto. The Central Heat switch allows the Webasto to be used to heat the water in both of the 10 gallon water heaters. The Interior Heat Exchanger switch heats the interior of the bus. By turning both of the Webasto switches on and the dash heater on while driving, it allows the fresh water to flow through all plumbing in the heat system.

After the 3rd draining, I removed the inlet and outlet hose from the Webasto and ran water through the system by using a water hose_DSC0424..JPG.

I also changed the cap on the fill tank. It was a Stant R3, NAPA P/N 703-1400. The Blank Coolant Filter is NAPA Gold 4070.

The picture shows fluid from the 4th and 5th drain. The 5th was a little clearer. Each time, I drained the water while still rather hot. I have a few more pictures of the process if anyone is interested.

[gmcbuffalo]

Dale what did you do with all the antifreeze contaminated fluid? Assuming your first, second and third drains had antifreeze in it.

Greg

[dale farley]

Greg, I use 5 gallon buckets and 55 gallon plastic drums. I have about 15 gallons in gallon containers so I can use it in my farm equipment. Our county dump collects all such materials.