Cooling System Maintenance

[Rod]

Hi All,

I have just completed some maintenance on my cooling system and there is a couple of things that I would like to share with you. After completing a complete drain of the coolant, I reverse flushed both the radiator and the block and realised I should share with you all the reverse flush tool I made a number of years ago.

I got a plug from Clarke Rubber and drilled a hole in the centre of it. After that I took a piece of copper pipe and flared over one end. With the non flared end I put it through the plug. From here I took a short piece of garden hose which had a male hose attachment and joined it to the copper pipe. After that I drilled a smaller hole and inserted a length of black plastic garden pipe. Done! Completed in about 15 minutes. A garden hose is attached to the the tool and bursts of compressed air is blown through the black tubing. It works a treat. I hope the photo's below are more valuable than my description above.

http://imgur.com/jiICiUZ

http://imgur.com/IkcoRaC

http://imgur.com/Uz3lGoG

The other thing I wanted to make mention is to be on the lookout for faulty radiator caps (new and old). I don't think the quality is there any more. My motor is running a treat but has just started to loose coolant hence the maintenance. I tested the radiator cap and sure enough it was not holding any pressure at all. I then took another second hand cap that I had and used it. Coolant still continued to be lost. At this point I started to get a little worried. I tested this and low and behold this wasn't holding pressure either. I then resorted to taking off the cap of my FE which has only been in place for a year and has only done a couple of hundred miles. Coolant loss was still present with this cap. Have a guess what - While slightly better than the other two this one didn't hold pressure either. These three caps were all the same - 7lb and I am sure they are / were tridon. They do however have CPC stamped on them.

Today I purchased a new cap (Tridon) which incidentally had slightly different wording on them and had no CPC or Tridon stamped anywhere. On closer examination of the cap it is manufactured slightly differently to the others. It has more of a "plug" than the others. I tested this cap and hallelujah this one holds 7lbs.

I do question the quality of the caps. I do find that I have had to replace them every couple of years due to coolant loss and / or rust developing under the cap.

Cheers

Rod

[Harv]

A garden hose is attached to the the tool and bursts of compressed air is blown through the black tubing. It works a treat/

That's a clever idea. I've made a few garden hose connectors for various flushing jobs, but never thought to add the air hose connection. Smart thinking. 

Cheers,
Harv

[mcl1959]

You are very correct Rod, radiator caps seem to fail without rhyme or reason. Even on late model cars they seem to be problematic, with more serious consequences.
The worst thing is that they don't look stuffed even when they are not working.

What method did you use for testing the caps?
Or are you lucky enough to have access to a professional test kit?

Ken

[Rod]

Ken I am glad I am not the only one who feels this. I was fortunate enough to have access to a pressure testing kit which comes with a radiator cap adaptor.

Rod

[mcl1959]

Your lucky Rod, one of the few items on an old Holden which is difficult for the home mechanic to test and make a value judgement on is the radiator cap.
Anybody have any method for testing a radiator cap without access to the specialised equipment?

There's an old joke about replacing a few parts on your old classic by turning the radiator cap anticlockwise and lifting it one inch, then push the old parts back and replace with the new parts. Lower the radiator cap and turn clockwise.
Sounds like you shouldn't even keep the radiator cap

Ken

[ardiesse]

Ken,

I can't pressure-test caps at home, but I can test the vacuum relief valve by pretending I'm a trumpeter . . .  If you put your lips around the rubber washer and blow, you can easily tell whether the vacuum relief leaks.  I've had a couple of new radiator caps on my FC over the past few years, and the vacuum relief valves always leak.  That's even after I clean all the sludge and scale out, between the washer and seat.  If I get the engine up to temp. and then then switch off, I can hear it gently breathe out the radiator cap.

If you've got an old radiator top tank, it shouldn't be too much hassle to remove the radiator cap fitting, solder some tube and a Schrader valve onto it, and connect it to a bike pump with pressure gauge.  Just thinking out aloud . . .

Rob

[hsv-001]

I use recovery tanks in my old cars and some have tops that fit a radiator cap so I just put the caps I need to test on one of these and pressure them up with my compressor and a gauge through the bottom hose inlet . Cheers Haydn