Coolant flushing kit - do i dare?
 

OK, last week I installed one of those Prestone coolant flusing T's in the heater inlet hose, thinking that I would flush the system this week. Then I got to thinking about the whole process, wondering what effect a backflush would have on the water pump. If I understand how the cooling system works, hooking a garden hose up to the heater inlet hose would force water backwards through the water pump and out the top of the radiator. That seems like it could put some serios stress on the pump.

Has anyone used a kit like this in the past? Any problems?

I would think that backflushing the cooling system would be totally unnecessary. I would suggest doing it if your water pump went bad. I would flush the system when the old pump was off.

A bad water pump can fill the system with little aluminum filings. It happened with my GL. It's ugly and it ruins radiators.

I'm changing the coolant in my SVX (had to take off the radiator anyway), but I'm not going to flush it.

As for whether or not it'll hurt your water pump, my only hunch is that it probably won't help it.

Re: Coolant flushing kit - do i dare?
 

Yup, I even have a pic of where the T is installed. I don't know about straining the pump, but mine still seems to run fine, but then again, summer is just starting. ;)

KuoH

We've been back-flushing them for years mainly because it disturbs the normal flow path and rinses away more of the debris that's collected over the years. Remember, most engines are sand-cast and over time more sand is released into the system. That's why some systems appear to have mud in them. (sand casting is also why there are 'freeze plugs' in an engine. they're not there for freeze protection but to allow the foundry to shake out the sand when the casting process is finished. their proper name is 'core plug'.)

It won't damage the water pump. If you elect to use a chemical flush be aware that if you have a marginal radiator or heater core the chemicals may finish them off. Another hint: don't go crazy with the water pressure.... and make sure you put anti-freeze back in the system for corrision protection.

All right, since I've already installed the T, might as well give it a shot. What would you recommend for draining the system before flushing? Just from the radiator valve, or do I need to take out those engine plugs too? I figure the plugs will be a PITA, but I'm concerned about getting coolant all over the place if I don't have the system drained well. Thanks for the advice.

Oh yeah, and just to make sure I'm not a total idiot, the heater inlet hose is the one coming out the passenger side of the firewall, right?

I'm not familiar with which hose is which hose and I'm already in the reclined position. :) As a rule of thumb the hose coming from the top of the engine is the heater feed and the one going lower, towards the radiator or water pump is the return.

I wouldn't pull the plugs, what would you do if one of them stripped? Say )*&(^&)*%#&%, maybe? heheheh Normally the water pump pulls cool water from the bottom of the radiator so make it so the water exits from the lower hose. It's also easier to control where the water dumps if you remove the hose from the radiator end. Have Fun! (anti-freeze and brake fluid are my two least favorite liquids to deal with.)

Except both hoses are on the top of the SVX engine. I was barely able to make out the arrow printed on the heater hose, and from that surmised that the passenger side hose is the heater inlet hose, unless it was installed wrong at the factory.

Oh, and as for antifreeze and brake fluid being your least favorite liquids, quit getting them in your mouth! ;)

KuoH

Shoot! Meant to ask one more question, but I forgot earlier. While flushing, should I leave the engine idling with the heater cranked up? Thanks again for all of your quick responses - this forum is really great.

No need to run the motor. Just make sure you run it a while when you finaly fill it up. To remove all the air pockets in the engine.
Happy flushing.
Harvey.

I have a question for Harvey - is reverse flushing for those of us on the top half the same as forward flushing south of the equator? I've heard that the water in the loo spins backwards down there, so I was just curious... ;)

You might want to put the lid down after you are done flushing so you don't get in trouble.:D

Just for the record, I've done all kinds back flushes, engine running, not running, hose blasting, hose dribbling, Prestone flush added, not added, etc. over the years on lotsa various cars. Nothing ever blew up or failed that I know about.
Now an SVX... Hmmmmm. Nah, it's still "just" a car.

Ron.

No every thing is normal down here.:rolleyes: ,,,,,,,,, It's you blokes, that are WAY over the top. :D .

Harvey.
(Nothing wrong with my water mate!):p :p

I also bought one of these kits, and was going to flush today, but didn't have enough time. I'd like to do it tomorrow, but I'm not sure exactly what hose is which. Which hose do I put the "T" fitting on???

Any other tips would be helpful.

Thanks!

- Rob