Radiator Sealant 'issues'

[Bluebelles Mom]

I just went out with a flashlight and let the car warm up. The leak is almost directly below the cap down at the lip of the upper tank in the front. It was a steady stream of water perhaps 3/8ths of a inch wide. Looked at closely the radiator appeared to be a bit bowed out in that area. I used a small pry bar to gently push it back into shape. I have called a local radiator shop and they quoted me a price of $89 for a new one and told me it would be more in labor if the fixed my metal one. He wasn't sure if he had any metal replacements and is checking before calling me back.

[hberdan]

If the tank is cracked it is best to replace the rad altogether. My current Tercel had the original factory radiator with metal top and bottom tanks, and had a crack in the top tank. I tried to repair it using a couple of recommended powerful metal epoxies , and nothing worked more than a few days. So I bought a new (plastic tank) one from Radiator Barn online. It worked fine for about 50K miles before it leaked, but it had a lifetime warranty and was replaced at no charge. The replacement has gone 60K miles without a problem so far, and still has the lifetime warranty.
It is a very easy job to replace the radiator, so when you can, just get a new one, and get new hoses at the same time. You will spend more than $89 on aspirin fretting about the old one.

[Bluebelles Mom]

Hmmm, the guy I talked with spoke of a 3 year warranty. Maybe I should shop around a bit more. I agree with replacing it and the hoses too, especially when he told me it would be more in labor to repair the old metal one. I wonder if I should bother trying another bottle of sealant? Or just add more coolant everytime she cools down? Sheesh, I can't wait until the 1st...this radiator issue is bugging me. The gate guards on base were all pointing at the steam today when I drove back on base...it's embarrasing.

[takza]

In cooler temps I'm pretty sure you could get by with just loosening the cap so the system doesn't build up pressure...you wouldn't lose so much that way. Just open just it far enough to keep the pressure from building up...

[splatterdog]

Stop leak is best used on repairs that greatly outvalue the car. A hundred dollar rad is pretty cheap. Load it up with stop leak and now it needs lots of flushing(which it might already need).

Don't ever run pure antifreeze! Water is a much better conductor of heat. Also, if it gets cold enough, straight antifreeze gels. 60/40 tops unless you are WAY north.

I know all about budgets, but you need a new rad!

Takza, the pressure cap is an integral part of the cooling system. Vented may work in winter, and only for a short time, but I wouldn't do it.

[Petros]

$89 is not a bad price for a new rad, plastic tanks or not (does it have a double row of tubes, like it should, or single row?). But I do not see how it is that much labor to fix a split seam or tear. Out MPV developed a tear in a tube (do not know why, but it was not that old), I used a propane torch and radiator solder (not the same as electrical solder) and fixed in about 20 min, including the pressure testing. An experienced radiator person should be able to do it even faster. Metal solder is how they are held together, repairs done properly are just as strong as a new radiator. The correct solder from an auto parts store is only about $4 or so last time I bought it.

Unless the guy was talking about doing a cleaning, that required unsoldering the top and bottom, running fine cleaning brushes through the tubes, and soldering it back together. That would cost more than replacing it, but not just fixing one seam.

[Bluebelles Mom]

$89 is not a bad price for a new rad, plastic tanks or not (does it have a double row of tubes, like it should, or single row?). But I do not see how it is that much labor to fix a split seam or tear. Out MPV developed a tear in a tube (do not know why, but it was not that old), I used a propane torch and radiator solder (not the same as electrical solder) and fixed in about 20 min, including the pressure testing. An experienced radiator person should be able to do it even faster. Metal solder is how they are held together, repairs done properly are just as strong as a new radiator. The correct solder from an auto parts store is only about $4 or so last time I bought it.

Unless the guy was talking about doing a cleaning, that required unsoldering the top and bottom, running fine cleaning brushes through the tubes, and soldering it back together. That would cost more than replacing it, but not just fixing one seam.

I don't know how much he was thinking of doing to it, he just said labor to repair would be more then the $89 for a new one. Nor did he say how many rows the new one had. Living in the NW does it make a huge difference? I don't plan on doing any serious off roading and certainly no racing with her.

I would be willing to go get a propane torch and some solder but now I am worried that the old rad might also need some serious cleaning out with the sealant I have put in. I think $89 is pretty cheap peace of mind, I just wish I could get it put in before the 1st.

[rer233]

sorry if i stepped on anybody's toes with my earlier post here. just trying to help. i agree with splatterdog - radiator time. petros- thanks for the welcome-prechiate it. as for where i got my info- it comes from a particullary painful experience i had 10-15 years ago. was doing a 'side job' on a m-b 300 sd that had a coolant seep at the back of the cyl head. the car had recently had valve guides replaced and the guy didn't want the head pulled again. so i put some coolant stop- leak in [don't think it was bar's leak- i think it was a silver powder.] anyway, it stopped the leak ok, but 2 weeks later, the car returned, running HOTT. checked it out- little or no circullation. t- stat checked ok [i should be so lucky!] pulled the upper hose- radiator core plugged. maybe the radiator was on it's way out before but it wasn't hot. long story short- i had to 'eat' a $375 radiator. not a lesson i'll soon forget! taught me not to try chemical solutions for mechanical problems. anyway, glad to be aboard and looking forward to talking to you guys!! ps- good luck bb's mom- i'm sure these guys will get 'er straightened out.

[rer233]

addendum to my latest post. problem with soldering- both surfaces must be VERY clean-almost impossible to do reliably without tank removal [just ask any plumber]

[Petros]

You know rer233, I would have tried flushing out the rad on the MB. It appears the sealant made a permanant repair on the head anyway. Perhaps it was the wrong stuff for the MB radiator, but I can not imagine the tubes are that small in the 300SD

I owned a 240D for a number of years. Great work horse of a car but they have a very odd cooling system. I do not recall that the radiator as anything too fine. It had a very large and durable looking radiator that never gave me any problems. The T-state and trapped air were the big PIA (factory manual was useless, I had to bleed all the air out of the engine every time I drained and refilled it or it would overheat).

[rer233]

petros i assume your 240d had the high- mount york a/c compressor. best way i found to fill the cooling system was to remove the t- stat, fill the block and head, reinstall stat, open the bleeder above it and burp the air out. you're right, they are tanks [although as a friend of mine once said "you have to make an appointment to get on the beltway" [at least with an a/t] ha.ha.

[hberdan]

Labor charges at any retail auto shop are always expensive. Petros, you're right, the repair may be a simple one, but the shop charges for minimums to make payrolls and compensate for jobs that take longer than they should on something else--just like plumbers and brain surgeons do. You know how to do the work but you don't charge yourself for labor...
FWIW, years ago I worked for an oil field service company that repaired rebuilt and services the big engines on drill rigs and oil pumping stations, etc, large engines which required regular PM. We routinely had radiators to repair, and those were always always always sent out to a radiator shop where they were completely stripped, acid dipped and completely cleaned, and then any repair and pressure testing was done on nice clean tubes and tanks. Even the cooling fins were straightened out. etc. with a special comb thing.
Any shop doing good radiator repairs on automobiles does pretty much the same--strip dip clean and repair, as it's hard otherwise to diagnose a specific leak and guaranttee a job as complete. Labor intensive.
Unfortunately, that forces some of us to use cheap Chinese radiators these days rather than paying for repairs and restorations of 25 year old radiators.

[Bluebelles Mom]

After a bad experience with a 'cheap' Chinese motorscooter a few years ago I really have an issue with using Chinese parts. I think I will ask at the shop just exactly how much it would cost to fix my old rad. If the difference isn't painfully bad I might just go with the metal one getting refurbished. Will have to see what they say.

[takza]

I have 2 radiators that are usable...(not trying to sell one). I got some parts from a 160K miles car of the same "generation" as mine...'83-'84...and put one in my car...replacing one with 220K miles that was getting green around the gills in places...no leaks...just had some fins that were corroded....some gone. One forum member showed a pic of a rad that had 1/2 it's fins missing and it was still in use. My guess is that they last longer than most comparable rads that were found in US cars of the same vintage.

But a split seam could be bad news...can't say. My guess is that they'd rather just replace than fix most stuff.

Some Chinese stuff is shoddy...some isn't. I can remember when the only thing Japan exported was cheap plastic toys...at least that was what was available...and then eventually Japan was noted for it's advanced tech and quality.