Stainless Steel Coolant Bottles

[PJ Grady (Europe)]

All,

A customer asked me about getting a new coolant bottle - and we got into a discussion about plastic versus stainless steel.
He was under the impression that stainless coolant tanks are 'bad news'. This isn't strictly true….and here's why…

The logic behind the idea that stainless is bad is that the flow of coolant circulating through the system creates an effective 'battery'. As the coolant flows across various different types of metal (the aluminium alloy in the block, the stainless bottle, etc), it begins to pick up electrons and starts to develop an increased positive charge. It's argued that this increase in charge can eventually start to cause corrosion from within.

This is technically true - and can be proven by taking a multimeter and testing the volts in the coolant - a voltage reading of a few tenths of a volt is normal - but anything much over a volt is a good signal that it's time to change your coolant!

In truth, the stainless coolant bottle doesn't dramatically increase the voltage over time - and if you follow the factory recommended 2 year coolant draindown interval - this will never materialise as a problem.

Incidentally - we don't sell stainless coolant bottles - not because of voltage - but because they're too time consuming to make and pressure test!

Happy driving.

Darren
(Chief Scientist)

[bozzzydmc]

Well said Darren, I completely agree!

I noticed on some Halfrauds coolant recently their claim it will last for 5 years, not that i would leave it in that long but it is a good sign of the technology behind antifreeze these days .

[Dan6457]

Ive just got a stainless bottle for DGS to replace the old plastic one and want to fit it this week. Ive never changed coolent on a rear engine'd car before. Whats the recomended way of doing it without getting air trapped in those long pipes? I've heard people talk about bleed kits, how do they work?

Any advice appreciated

[JamesRGUK]

Dan1986 Wrote:Ive just got a stainless bottle for DGS to replace the old plastic one and want to fit it this week. Ive never changed coolent on a rear engine'd car before. Whats the recomended way of doing it without getting air trapped in those long pipes? I've heard people talk about bleed kits, how do they work?

Any advice appreciated

The bleed kit is simply a pipe which attaches to the top of the water pump bleed nipple and leads back to the header tank by 'T'ing into a small return pipe. it effectively allows any air locks at the top of the pump (the highest part of the coolant system) to find their way out of the system.

There have been a few discussions as to wether or no they really do work, but the general consensus is that they are worth having I certainly know many owners who have them installed.

It's a 5 minute job to install and you can get all the parts for around £5

James

[Chris Williams]

It's also worth having the car on a slope, nose down the hill to allow the coolant to flow better, and fill slowly.
Chris

[stunned_monkey]

PJ Grady (Europe) Wrote:... "and if you follow the factory recommended 2 year coolant draindown interval - this will never materialise as a problem."

How many DeLoreans have come through your hands where the coolant is brown with rust from the cylinder liners? Funnily enough we have it pretty good with the DeLorean: The coolant pipes are aluminium. The Alpines have steel coolant pipework!

The self bleed kit 100% definitely does work... -IF- the bleed hose travels uphill to the bottle. If you pipe it down and then back up again, you've greated a U-bend and the air will get trapped just as before.

Alpines (310, GTA and A610) all have a coolant bleed off from the upper (stat housing) hose that returns to the top of the coolant bottle.

I have my bottles made with an extra barb at the upper rear edge to take the return from the stat housing.

I have all the parts in stock to make up several self-bleed kits.

After completely draining a coolant system (bottom right rad hose is easiest), flush both sides of the system, through the bottle and the hose going to the stat housing. After filling up with 50/50 anti freeze and water, bleed the radiator by removing the top right hose. Repeat several times and you'll find each time a little less air comes out. Keep doing it till no air comes out at all. Then run the engine with the ar$e of the car jacked up otherwise you can get an air lock in the heater matrix.

[Guinney1971]

Phill made his own self bleed kit for Sorbet, parts cost about £2.00

A problem that his car had a year or so back though, was that the car was
chucking water out of the overflow because the cap on the water bottle had
failed and it wasnt pressurising the system properly - basically the car would
drive fine and not over heat, but then as soon as he stopped, the car would boil
up and spew hot water everywhere.

Luckilly RichH came to the rescue with a spare cap until such time as a new one
was purchased

[Dan6457]

Thats ok I got a brand new cap with the bottle Thanks for the advice, I don't think I'll bother this week in case I split a hose or somthing and can't drive the car to the show at the weekend! I'll get onto it next week. Cheers for the advice!

I'm assuming when I put the bleed hose on I then leave the bleed nipple unscrewed all the time. Do motor factors usualy sell T pieces suitable for this?

[TheOriginalMrP]

I wouldn't worry about changing that bottle Dan. I changed mine in 5 mins, and I think the possibilities of an airlock are slim, unless you fill it up using a pressure washer or something! 2 bolts, 2 hose clips, and thats it. Just top up the new SS tank steadily before you fire the car up. Then start her up, and let it idle for a few minutes with the cap off before switching off, toppinng up if necessary, and replacing the cap.

You are more likely to have an exploding plastic bottle than to have any problems fitting a SS tank.

Ben

[Dan6457]

Thanks Ben but I want to change the coolant as Ive no idea when it was last done and I did the oil the other week so it would be peace of mind to know everything is done.

[bozzzydmc]

If your just changing the bottle just remove the lower hose from this and drain that bit of coolant out of the bottle, that way the rest of the system is left untouched .

[Dan6457]

I might do that for now but I want to change the coolant asap as I've no idea when it was last done.

[JamesRGUK]

Dan1986 Wrote:I'm assuming when I put the bleed hose on I then leave the bleed nipple unscrewed all the time. Do motor factors usualy sell T pieces suitable for this?

No you replace the nipple with a straight through barb or you can drill through your exiting nipple, it's only soft brass.

Sorry that all sounds rather painfull :-)


J

[Dan6457]

I see! Thanks for clearing that up. I'll probably change the bottle over tomorrow the change the coolant and make the bleed kit next week as I need the car in one piece for alexandra palace at the weekend.

Cheers, Dan.

[stunned_monkey]

JamesRGUK Wrote:you can drill through your exiting nipple, it's only soft brass.

You don't get much length to attach the hose to though.

...er does that sound rude?!