Prestone question

[Fotoman]

I started disassembling some parts of my engine (FL 120) to service them and paint them over the winter. Today I attacked the prestone system. I took out the tank and I have a few questions.

First I thought I would find a gasket between the tank flange and the block but it looks more like rubber than anything else (see picture). What is it exactly?

Then I noticed there was a spring in the elbow hose. Why? To prevent it from collapsing?

Finally the inside of the tank is pretty dirty with some goo that looks almost like mud. I rinced it with water but I'm wondering if I shoudl/could clean it better with some chemical.

As always your help is very much appreciated.

 

[Forkliftt]

Eric,I'm gonna take a run at this. The "rubber" I think is red silicone. I would remove all of the old silicone and use the tank as a template to "cut" a new gasket with. You can purchase gasket material from NAPA. I use a 4 oz ball peen hammer to "cut" the gasket material. Use the non flat end- cut the two bolt holes first, then gently tap around the inner circle and outer shape. You are right about the spring- but you will usually find them on the suction side of your engine water pump so it may not be necessary at that location. I would certainly clean the tank- maybe an AC coil cleaning solution or aluminum cleaner? You are painting the exterior anyway so something pretty strong would probably be fine.
I admire your approach and have thought of the same approach when I get time.

 

[Roostor]

I agree with Steve, some very good advice there, especially on making that new gasket; and I would only add that the whole system should be "flushed" as whatever is in the tank is also in your cooling system.

 

[FF]

and I would only add that the whole system should be "flushed" as whatever is in the tank is also in your cooling system.


On most diesels the proper PM is drain and use a 2 part flush every 3 years or so.

ONLY the 2 part will get rid of most of the goop that settles out of the antifreez.

On a modern engine that must use diesel antifreez (exposed cylinder liners) (not Prestone) this is a manditory procedure.

 

[jleonard]

"On most diesels the proper PM is drain and use a 2 part flush every 3 years or so"

That is what I do except I usually* skip the flush compound.
Personally I would not bother making a gasket I would use straight sillycone gasket maker.

 

[RT Firefly]

Hiya,
** All good advice.* I would either buy a proper gasket from American Deisel (looks like a Lehman) or go to an auto parts store with the tank and they should be able to match the pattern pretty easily.* As a last resort (for me) I would follow Mr. Forklift's suggestion.* As I mentioned previously, I really don't like silicone which I consider a cheap and dirty fix for anything but toilets.
P.S Just saw Mr Keith's post-yup, replace the thermostat while you're at it.

-- Edited by RT Firefly on Sunday 5th of December 2010 09:29:40 AM

 

[Keith]

I'd replace the thermostat while you're in there. You get that and a gasket from American Diesel, or just use the RTV silicone gasket goop. The spring is there to keep the hose from collapsing. I'd also replace those hoses while you're there. American Diesel - 804-435-3107. I flush mine every three years, but have never seen the two part stuff FF mentions.

Be sure to dilute the anti-freeze with distilled water, not tap water.

 

[Forkliftt]

Eric,
Obviously you have planned poorly for your project. It appears you possibly didn't order new hoses, a new thermostat, a new cap, coolant and radiator flush. And possibly you didn't allow 3-5 working days to get a new gasket in. Who would have thought that painting your engine could be so complicated?
Go ta NAPA, cut a new gasket, apply silicone (your color choice) to both sides of your new gasket and complete your initial job. Maybe you will get lucky and the darn thing will run till you get ready to service your cooling system!

 

[Fotoman]

Thanks for you replies.

Steve, I'm learning as I go along. No need for me to plan things that much since the boat is on the hard until May (I'm in Canada). I'm making a list of all the things I will need from American Diesel and will place my order in March or April when it's time for me to put everything back together.

I will change all the hoses and keep the old ones as spare. Didn't think about the thermostat but why not. I noticed two sensors right under the tank, Should I change them as well?

I will also flush the system next spring and change the oil coolers. Next week I'll disassemble the heat exchanger to take a look at it and clean it.

Steve, I should put a gasket AND silicone?

 

[Forkliftt]

Yes,
If I am installing a part that may get removed in the near future and I want to possibly reuse the existing gasket I would consider a sealant only on one side. For the most part, the convenience of reusing an old gasket is not nearly worth the inconvenience of a small leak that sealant on both sides might have prevented. Silicone only is seldom used.
My favorite "sealant" these days is HI Temp Silicone for most applications. Anything around fuel, such as an intake, I prefer Loctite Anarobic sealant.

 

[Keith]

I wouldn't bother with the sensors unless you suspect them of being bad for some reason. I always put a thin coat of blue or black hi temp silicone on the gaskets on both sides. Kinda belt and suspenders, but one thing I've noticed is that a thin silicone coating on the inside of hoses and other stuff both seals them and makes them easier to remove years later. The rubber doesn't "weld" to the metal like it does without the silicone caulk.

 

[Tidahapah]

If using a good quality jointing (gasket) material then the only application required is a smear of anti seize grease Koper kote or similar. This will ease the removal next time.
Ensure that the surfaces are clean and flat.
If a cold water seal then rubber insertion jointing should be used and no grease at all should be used.
Call me old fashioned but I have been doing this for over 40 years and it has allways worked for me.

The more sealants you use the more chance you have of getting gunk in coolers or in thermostats and other places.

Benn

 

[Fotoman]

What's the proper procedure to do a flush?

 

[Fotoman]

Before and after.

 

[RT Firefly]

Hiya,
** That's the stuff Mr. Fotoman!* BUT you realise you've made a MAJOR mistake.* When you put that purty "new" tank on your engine, the rest of the engine will look shaby by comparason sooooo...now you have to do the rest of the engine.* It's all good at the end until you take a look around your ER and you start a re-furb' on the ER until you look at your saloon floor so you do a.......you get the idea.* Looks good in any case.

 

[Fotoman]

RT Firefly wrote:

Hiya,
** That's the stuff Mr. Fotoman!* BUT you realise you've made a MAJOR mistake.* When you put that purty "new" tank on your engine, the rest of the engine will look shaby by comparason sooooo...now you have to do the rest of the engine.* It's all good at the end until you take a look around your ER and you start a re-furb' on the ER until you look at your saloon floor so you do a.......you get the idea.* Looks good in any case.

Yeah, I know. But one thing at a time and eventually everything will look the same: nice and shinny.

*

 

[FF]

Simplest , tho not cheapest is to go to a DD dealer and purchase the chemicals.

They come in rather large sizes ,(my bus conversion uses 100Q to refill) so split with the folks on the dock.

This is supposed to be a 2 or 3 year procedure , for some its been 30years!