Coolant / Antifreeze for 1994 K75

[heejrbmw]

I searched the threads for antifreeze and did not feel like a got a definitive answer regarding antifreeze that can be used successfully in a K75. I saw info recommending BMW brand and I believe GS something or another. I forgot. I'll have to look at it again. I don't have BMW antifreeze available within 120 miles. I went to the local parts store and read the labels on various brands of antifreeze. On the Prestone Extended Life Antifreeze/Coolant, the label says:
"Silicate, phosphate, borate and nitrite free"
"Extended protection to all engine cooling system metals including aluminum"

This is concentrate, so I'll have to dilute to 40/60. Does anyone think there is anything wrong with using this antifreeze in a K75? I can order the BMW mail order if that is what I need to do.

Thanks,
Ed

 

[breyfogle]

I searched the threads for antifreeze and did not feel like a got a definitive answer regarding antifreeze that can be used successfully in a K75.....Ed

You probably never will get a definitive answer. BMW recommends their house brand coolent and there are alot of Kbike owners that will go with whatever BMW recommends. Personally, as long as the container says something like "safe for aluminum" and it is a name brand you are probably OK to use it. I have put 130+ thousand miles on my K75S and have always used plain old Prestone without a problem.

YMMV however .....

 

[35634]

You probably never will get a definitive answer. BMW recommends their house brand coolent and there are alot of Kbike owners that will go with whatever BMW recommends. Personally, as long as the container says something like "safe for aluminum" and it is a name brand you are probably OK to use it. I have put 130+ thousand miles on my K75S and have always used plain old Prestone without a problem.

YMMV however .....

ditto, 180k+

 

[kgadley01]

I went to the local HONDA dealer, and bought theirs. Its already premixed.

 

[Zagando]

I know and understand your dilemna---went through the same quandry with my '94 S as you. While Prestone or other easily available may be fine I ended up going with a Swiss pre-mixed antifreeze whose name escapes me at the moment (I'll look downstairs in the morning as I know I still have some left)---and post the name then. It was blue and seems to work fine so far. I got it at the local Suzuki dealer.

Sometimes it's worth the extra cost to use something that you can be certain is free of harmful substances for our beloved machines and also acheive peace of mind in the process.

 

[pglaves]

There is nothing about the K75 cooling system that is particularly fragile. Normal antifreeze works just fine. Avoid any that use solids as abrasives to keep things clean. The Prestone notation "Silicate, phosphate, borate and nitrite free" is sufficient.

Years ago many Goldwings had water pump seal failures from using antifreeze with solids which abraded the seals but the K bike seals are different. Avoid the solids anyway!

Be sure it is approved for aluminum engines.

 

[heejrbmw]

Thank you one and all for your responses. I feel like I'm fine using this particular formulation of Prestone based on the responses. That is good to know. I feel like any time I need anything, including consumables, I need to check the forum and I always get valuable responses. Thank you very much for taking the time to reply to newbies like me!

Ed

 

[Zagando]

Sorry this is so late and after the fact but the antifreeze whose name I could not recall last night is Motorex.

 

[PHMARVIN]

Prestone is fine. Me being a cheap SOB (frugal is a nicer word), I use WalMart's brand, mixed 40/60 with DISTILLED water.

 

[98lee]

Phil brings up a great point: DISTILLED WATER!!!

You don't want all the crud that is in your domestic water supply in your radiator. You know the stuff that builds up on your shower door. Even worse if you live in an area where well water is a large part of the water supply. And who knows what fluoride does to seals or aluminum.

 

[Zagando]

And who knows what fluoride does to seals or aluminum.

Why that's simple; prevents cavities!

Sorry, guess I have nothing better to do today...

 

[98lee]

Jeff,

Is that bike running yet?? If you're not careful it's going to turn YELLOW with non-use.

 

[deilenberger]

One other tiny point..

If you are changing the antifreeze, it's worth making certain that ALL the old stuff is out of the system. This is especially the case if you're going with one of the GM long-life coolants. There have been reports of those creating a gel like substance after being mixed with "normal" ethylene-glycol antifreeze.

It's not a bad idea anyway. And as others mentioned - distilled water is a good thing.

 

[PHMARVIN]

In case anyone is interested, the following is how I change my coolant:

1. Remove fuel tank to access fill connection. Remove fill cap.
2. Remove coolant drain plug. Drain coolant (into a pan for correct disposal).
3. Place garden hose into radiator fill tube. Turn on water to slowly fill system.
4. Start engine. Water from garden hose is going through engine and out onto the ground. Run engine for a few minutes.
5. Stop engine. Allow water to drain. Replace drain plug.
6. Fill system with DISTILLED water. Start engine and run for maybe a minute.
7. Remove drain plug and drain system.
8. Reinstall drain plug and tighten, this time with new gasket. Fill system with a mixture of 60% DISTILLED water and 40% anti-freeze (I use Wal-Mart's brand or, if cheaper, whatever brand is on sale).
9. Start engine and run until thermostat is open. Check coolant level and top up as necessary.
10. Empty overflow bottle and add new coolant to above the "low level" mark.
11. Reassemble everything (overflow bottle, radiator fill cap, fuel tank, etc.) and go for a ride.

 

[tourunigo]

all of this is very timely for my current reassembly of K1100 cooling system. Thanks. - Bob

 

[heejrbmw]

Great information folks. Thanks very much.
Ed

 

[mieczkow]

Coolant

I use Motul Factory Line red coolant in my 1987 K75S and have had excellent success with it even in the heat of Florida summers. It's a bit pricey but worth it in my opinion