Replacing cooling system in D1 - seeking words of wisdom

outono

outono

Well-known member
Sep 26, 2020
162
85
Orange, CA
Replacing the radiator, water pump, thermostat, and coolant tank. Im also throwing on a new fan clutch and condenser fans.

The hoses all look to be in good shape since the previous owner dropped a used engine in about 2 years ago. Looks like they put new hoses in too. Passing on replacements here, hope this doesn't bite me in the ass...

I've got a few questions and im hoping some of you can impart some good advice while doing this:

1. Should I be using Permatex #2 on the thermostat and water pump (it'll be used in conjunction with gaskets)? I've seen a couple videos of people doing this, but it's not clear that it's appropriate.

2. What's the best way to drain the coolant? Bolt on the water pump? Pull a hose?

3. Recommended coolant flush technique? I can't imagine it looking too bad since the engine did get a bit of a refreshment a couple years ago, but you never know. Is throwing distilled water in, running for 10 minutes, and then flushing it out enough?

4. Worth replacing the water pump bolts?

What else am I missing?
 
Frobisher

Frobisher

Well-known member
Dec 27, 2012
202
69
Pennsylvania
outono said:
Replacing the radiator, water pump, thermostat, and coolant tank. Im also throwing on a new fan clutch and condenser fans.

The hoses all look to be in good shape since the previous owner dropped a used engine in about 2 years ago. Looks like they put new hoses in too. Passing on replacements here, hope this doesn't bite me in the ass...

I've got a few questions and im hoping some of you can impart some good advice while doing this:

1. Should I be using Permatex #2 on the thermostat and water pump (it'll be used in conjunction with gaskets)? I've seen a couple videos of people doing this, but it's not clear that it's appropriate.

2. What's the best way to drain the coolant? Bolt on the water pump? Pull a hose?

3. Recommended coolant flush technique? I can't imagine it looking too bad since the engine did get a bit of a refreshment a couple years ago, but you never know. Is throwing distilled water in, running for 10 minutes, and then flushing it out enough?

4. Worth replacing the water pump bolts?

What else am I missing?
Click to expand...
1. I think I used Hylomar on the gasket.
2. Siphon the coolant out of the rad to get most of it. Middle school science applied.
3. I just hooked up the garden hose and flushed it through since I was installing a new rad. It seemed easy enough and the water was then pushed out by the coolant later. Opinions might vary on that…
4. Unless the bolts look nasty, I reuse them, but there’s nothing wrong with making things new and shiny. The only bolt I broke in this repair was on the thermostat. It was early in my ownership and skill development, so it was a little disconcerting. Things don’t always come off the way they’re supposed to. It helps to be prepared.
 
  • Like
Reactions: eburrows and outono
terryjm1

terryjm1

Well-known member
Jan 23, 2011
1,489
375
For the water pump, the long bolts that go all the way through the front cover sometimes get rusty. It is also possible to strip the small heads of the bolts. A previous owner may have already started that process. Be sure to use a good snug socket. I like to have a couple spare long bolts on hand in case they are needed. Also, be sure to get the correct thread locker for those long bolts as they seal coolant in the block. Do your best to get those threads clean inside and make sure it is dry when you put it back together. On the gaskets, use very little sealer, a very thin coating. I know many mechanics use no sealer as all.
 
outono

outono

Well-known member
Sep 26, 2020
162
85
Orange, CA
Thanks for all the recs.

boxster said:
Maybe a Flow Kooler water pump instead of stock pump.
Click to expand...
Ya, that's what i've got. Hoping for some good results!

terryjm1 said:
For the water pump, the long bolts that go all the way through the front cover sometimes get rusty. It is also possible to strip the small heads of the bolts. A previous owner may have already started that process. Be sure to use a good snug socket. I like to have a couple spare long bolts on hand in case they are needed. Also, be sure to get the correct thread locker for those long bolts as they seal coolant in the block. Do your best to get those threads clean inside and make sure it is dry when you put it back together. On the gaskets, use very little sealer, a very thin coating. I know many mechanics use no sealer as all.
Click to expand...
Any idea what the correct threadlocker is? Is it in the RAVE manual?
 
terryjm1

terryjm1

Well-known member
Jan 23, 2011
1,489
375
I use Loctite (I think 243) for the water pump bolts that go into the block. 243 is off the top of my head, though. Can anyone confirm that? If nobody confirms it, next time I am at my shop I will look at the tube I have on the shelf.

572 also just popped into my head.
 
WaltNYC

WaltNYC

Well-known member
Mar 3, 2010
710
138
NYC
when replacing the water pump make a outline of the pump in cardboard and insert the old bolts where they were in the pump. That way you will have less chance of putting a long bolt in the hole for a short bolt and ruining your block.
 
  • Like
Reactions: Jimmy, Frobisher and outono
You must log in or register to reply here.
Top Bottom