While changing the thermostat in the '91, I noticed some stuff growing in the radiator, around the tubes... I messed with it a little and found it to be hard, like calcium or lime or the stuff you would see inside a hot water heater... My question is, what is a good radiator flush? One that would work to remove the stuff while the radiator is still in the truck...? I could take it out and have it rodded out but really don't think it is necessary as there are no cooling problems... the thermostat was working but after reading a few posts on here, I decided to change it out as my gage would wander every now and then.... now it wanders all the time.

 

as long as you don't have a over heating problem, i wouldn't worry about it. Some of the flushing agents will do more harm than good. One thing you need to do is change the antifreeze, every couple of years, and use a good quqlity anti freeze, some of the cheaper brands don't have as good anti rust aditives in them.

 

Did you bleed all the air out of the system? A pocket of air can cause a wandering gauge.

As for the flush, Just flush it backwards with water if you are worried about it. Then, as said before, use a good quality coolant.

 

Calcium, Lime, & Rust remover

 

There's a 50/50 possibility that stuff indicates you have a leaking radiator. A flush may break it lose and cause it to start leaking more.

 

I think the stuff you are talking about is called Solder Bloom and is caused by the degradation of the inhibitors in the coolant.

I have it in mine and I already have it planned to have a custom radiator built as soon as it starts to give me problems. (The money is already set-aside for it)

Talking to my Radiator man he says that almost all radiators will die from this.

I hope the cooling system filter I have installed will help prevent this in the future if nothing else gives me pretty green coolant.

I found a link that has some pictures.

http://www.arrowheadradiator.com/Rad...20Failures.asp

Also your wandering temp gauge could be caused from a poor ground on your instrument cluster or an air pocket as already mentioned.

Jim

 

Fleetguard makes a coolant flush product. I bought some from my local Cummins dealer but haven't tried it out yet.

 

After looking at the link that Jim Lane sent, it is in fact, "solder bloom"... I have never heards of it before but it looks just like that. Caused by inadequate stuff in the anti-freeze. I guess I should have changed it out before now... Anyway, I will make and attempt at flushing it and hope that I have caught it in time. My neighbor owns a 1-800-RADIATOR store. They give a lifetime guarentee!! Including labor. Hope I don't have to go see him...wanted $250..... Thanks again for the replys....

 

Modern flushes are acid based, if its bad it will start leaking. If its not over heating wait till you can pull it and have it done properly.

 

ok i got to ask if you were putting a spanking new radiator in your ride would it be the plastic aluminum one , or all brass, or what.

 

Plastic and aluminum is my preference.

 

I'm kinda old school.. copper or brass... but aluminum has come a long way.. I guess I like brass because its easier to fix....Plastic on this truck is out of the question... seems like the plastic ones would be easier to break.. I'm leaning over that thing all the time..lol

 

Aluminum is a better conductor that copper or brass. But in order get same structial strengh aluminum rads are thicker, thicker means less heat dissapated. So i'd go old school.