Flushing Radiator and Replacing Hoses --- Suggest?

[mrstinson]

I am going to be replacing my radiator hoses and thermostat this weekend and at the same time flush the system. I have read a few posts and will listen to them as best I can. But I was wondering if anyone has any suggestions or some "heads up" that I should be aware of?

Also what is the best mixture of antifreeze to water for a Cincinnati winter? I just moved here and don't really know how cold it gets.

Thanks for any help.

 

[dklawson]

Is this a late Midget with a 1500 or is it an earlier Spridget with an A-series engine?

If it's an A-series, spray the nuts/studs for the thermostat housing with penetrating oil, strike the heads of the nuts with a hammer and repeat the process a couple of times. Do this each day between now and the weekend. Hopefully the oil will work its way down into the gap between the t-stat housing and studs. Assuming this helps and the nuts (or studs!) come off the head your next task is removing the t-stat cover which may be corroded in place. Start with more penetrating oil on the fasteners going through the t-stat housing. Whatever you do, don't pry up on the hose neck of the housing. This may be heresy, but I use a sharp chisel or putty knife between the head and housing working my way around with gentle taps. Once it starts to move I use the putty knife to pry the housing up a little at each spot, working my way around the housing. If you nick the head or the housing, dress them flat again with a flat file on the block and sandpaper on a glass plate for the housing. I replace t-stat housings using stainless bolts instead of the regular steel hardware and I coat the threads and shanks of the bolts with anti-seize compound.

 

[sparkydave]

I'd echo Doug's comments, and if you do have a 1500, there is a drain plug on the right side of the engine block below the exhaust manifold. I have found that it helps to take a piece of 1/2" heater hose to stick in the filler plug, and I blow into it after the drain plug is removed. This helps to get more of the old coolant out. If you don't have this option, it helps to go through a few rounds of filling with pure water, running the engine until the thermostat opens, and draining it until what you drain out is basically clear. If you really want to flush effectively, take the thermostat out, and use a hose to flush the block. Disconnect the radiator and heater hoses and flush the radiator and heater core opposite the direction of coolant flow. Antifreeze mixture should be 50%. Around here it's rare for it to get below zero, and the coldest I recall was -10. Be aware that going to a 70/30 mixture which gives you the lowest freezing point doesn't remove heat as well as 50/50, so if you decide to go with that you might want to change to 50/50 come spring.

 

[mrstinson]

I have a 71 Midget ( I just added a signature so don't think that Doug and Dave don't read). It looks like most of the bolts have been removed in the last 10 years so they do not look stuck on, but I will spray them anyway just to make sure.

I was going to add Water Wetter to the mixture, but was not sure what mixture I should go with. I will put a 50/50 mix in for winter, but should I change it for summer? The reason I ask is becuase of how hot it was this summer.

BUT - it looks like I will have to wait to do the flush becuase I ordered two of one hose and didn't order another (in fact the one I am missing is the one I need the most, the other were a becuae I am doing it replacement). So it looks like I will need to order the hose from Moss because Autozone doesn't even offer the part.

I can always check the points this weekend instead. /ubbthreads/images/graemlins/grin.gif

 

[spritenut]

Re: Flushing Radiator and Replacing Hoses --- Sugg

What Doug said about the t/stat housing. Or at the very least, sand down any pits on the underside of the cover and neversieze the threads.
To flush the system, pull off the hoses, run clean water thru the radiator and watch for clean water to flow out where the lower hose was. Pretty much the smae on the block but run it in the t/stat cover and watch it clear up out of the water pump.
I would use a 50/50 mix. I run 50/50 year round.
As for water wetter, it's just dish soap. Soap breaks the coheasion factor of water and makes it *wetter* It's an old model railroader's trick for making elmers glue flow on landscapes. Just look under the sink and only a few drops or teaspoon at most. Car wash works even better as it;s low sudsing.

 

[jcatnite]

Re: Flushing Radiator and Replacing Hoses --- Sugg

Is that all water weter is? I thought it was something a little more scientific than that. We used to add octal alcohol to the Lithium Bromide chiller plants to break down the cohesiveness of water. The old salts used to tell me that it made the water "wetter". It would seem to me that soap would actually increase it's cohesive propeties...I guess a little might actually do that but be very careful not to add too much as it would seem that it would raise it and make things worse. You don't want foaming in your system. The water pump will become foam bound and stop pumping...
JC

 

[ChrisS]

Re: Flushing Radiator and Replacing Hoses --- Sugg

I run 50/50 year round as well without any issues. I’ve spent some time in Cincinnati and the weather is the same or milder than the weather in MA.

Water wetter is really only needed if you want to run straight water to help with cooling. It helps a little in a 50/50 mix, but not worth it in my option. In addition to reducing the surface tension water wetter also has corrosion inhibitors and lubricant for the water pump bearing which is part of the antifreeze mix, but needs to be added if running straight water.

Octal alcohol on the other hand is really only for chilled water loops in HVAC applications. It does a few things, some of which are urban legends and some are real. You wouldn’t want to run it in a system operating at an elevated temperature due to high evaporation looses, but this isn’t a heat transfer forum so I digress.

 

[dklawson]

Re: Flushing Radiator and Replacing Hoses --- Sugg

The $10 word for Water Wetter is "surfactant"... which soap is also. I run a mix of Water Wetter, anti-freeze, and water.