Burrrrp! Excuse me…

[HerrBGone]

(Caution – Long Post)

Today was a good day! I finally got Thunder’s cooling system burped and there is no more air in the lines. WooHoo! As a result, the blinky red light no longer comes on except at self-test and the temperature gauge reads in the normal range. This is a notable departure from his behavior up to today. In the process I may have cooked up a new technique for getting all of the air out of the lines.

This could be dangerous so be extremely careful if you try this. You have been warned.

OK, here’s what I did:

First, with the van sitting level, and both heaters turned on full blast, I removed the hose to the overflow tank, then opened the pressure bottle and topped that off and closed it, then reconnected the hose. Then, having first removed the upper grill, I started the motor and opened the radiator bleed valve to let the air come hissing out. I tried to bring the engine up to an even 2000rpm with my hand on the gas pedal while I watched the tach swing wildly from 1500 to 2500. It turns out working a gas pedal by hand isn’t as easy as it may at first seem. I did eventually get the hang of it and got used to the sound of 2k/rpm. Getting any coolant to come out of the radiator took a several tries since there seems to have been quite a bit of air in the line. With the vent opened and the engine running at idle I went around to the back of the van and checked the contents of the pressure bottle. Half full of air. Back to the front, close the bleed valve, shut off the motor and refill the pressure bottle.

Rinse and repeat. (This would be much easier with one or two helpers…)

After several cycles of the above, I turned Thunder around to use the slight rise in the yard where I was working to put the back end a bit higher and backed up onto my ramps. I had adjusted the driver’s side mirror to be able to see the back tire and ramp so I would have some idea of when to stop. This was rather entertaining because as I backed up onto the ramps I noticed a rather large moth that turned out to be in birch bark camo going for a ride on the sidewall of the tire. It must have gotten dizzy because it stayed there throughout the rest of the job.

Where was I? Oh yeah…

With the back end of the van elevated to where I could reach things without having to bend over near as much, I went thorough the same procedure as before without opening the radiator bleed valve and bringing the revs up to about 2k with a hand on the linkage at the FI so I could watch the bubbles burp out of the top hose and into the pressure bottle. Then I went in the house for a while to give my poor ailing back a rest. During the intervening time the system took some coolant from the overflow tank behind the license plate. Hmm… Things seem to be starting to work the way they’re supposed to. This is a good sign. I didn’t disconnect the hose to the overflow from this point forward.

I refilled the overflow tank to the max mark and restarted the engine. As I watched the pressure bottle gradually fill about half way with air I had a brainstorm!

This is where it could get dangerous.

DO NOT TRY THIS WITH THE ENGINE UP TO OPERATING TEMPERATURE!

With the motor running, but not yet up to temperature, I slowly opened the pressure bottle cap about a quarter turn. Just enough for the pressure inside to slowly force the air out. Then I quickly closed it as soon as the first drops of coolant came out. It’s easy to see what’s going on inside the bottle level-wise to be ready to close the cap tight again just as the fluid reaches it.

Keeping the motor running I repeated this bleed at the bottle technique until I could see no more air in the bottle. Then I made sure the overflow tank was filled properly and kept an eye on things with the engine running for several minutes. At this point if more air had shown up I would have let things cool before opening the bottle again as I would imagine there was getting to be a good bit of pressure build up in the system.

Part way through all of this I turned on the A/C fan just passed the click to start the radiator fan to get some airflow up front just to keep Thunder from overheating now while I was working to keep him from overheating later. Since the A/C compressor’s belt was removed by Thunder’s PO it didn’t add any load to the engine, but did make the radiator fan switch on. I may be replacing the fan switch in the not too distant future, since I have never heard the fan come on on its own. That’s something to keep an ear out for now that the lines have been bled and it’s starting to warm up what with the coming of Spring.

Everything seemed to be fine and dandy at this point, so I shut off the motor and put the grill back on and tidied up all of the tools I’d been using for various little tasks and went for a ride to a local restaurant for lunch.

I checked the overflow bottle when we got there and there was slightly more antifreeze in the bottle than when we left the house. I guess that’s to be expected with the fluid expanding from the heat. I checked again on the way out and it looked about the same. Since the blinky light was only coming on for self-test and the temp gauge was reading normal we took a bit more strenuous of a ride of about fifteen miles up the highway to Ocean State Job Lots in Gardner Massachusetts. Up hill most of the way. The light stayed out and the temp never went more than a needle width above half on the gauge. This is a first since I’ve owned Thunder.

When I checked the overflow tank at Ocean State before heading home it was almost full! More than three quarters of the way up the cap. Not that I would open that cap then, but, if I were foolish enough to, it would have dumped a cup or two of antifreeze all over the muffler.

Is this normal? Have I somehow overfilled the system? Or is too much of a good thing just right?



Edit: Filled in a couple of missing steps, expanded and elaborated. (Yeah, I made it even longer. Sorry… )
_________________
HerrBGone
(AKA: Dave)

A fellow wanderer on the road less traveled

Fritz, '71 Superbeetle
Galileo, '98 New Beetle
Thunder, '85 Vanagon Westfalia (full camper)

[weinerwagen]

Sounds normal to me....
_________________
Retired attorney--Tort King.

[HerrBGone]

Ah good! I feel much better. I was afraid it might be "abi-something."
_________________
HerrBGone
(AKA: Dave)

A fellow wanderer on the road less traveled

Fritz, '71 Superbeetle
Galileo, '98 New Beetle
Thunder, '85 Vanagon Westfalia (full camper)

[Yellow Rabbit]

I did the same thing last weekend. Here's a good hint. Do not install the front bleed screw only 1-2 threads. When the coolant reaches the radiator, the screw goes flying across the garage. It also helps to have a helper.

I did not raise the van. I filled the bottle until coolant came out of the rear heater bleeder. Then I ran it until the front bleeder flowed coolant. Then I went for a short drive, bleeding the front a couple times out on the road. Then I stopped on my inclined driveway, bled one last time, and topped off both tanks.

The needle reads slightly over half way which seems to be normal for my van. Both tanks are at the same level after a week.