Over flow bottle

[Yanmar_1700]

I happen to glance down at my temp gauge and noticed my normal 170 degrees was 210 on my YM1700. I looked at the overflow botlle and it was at the same level. When it cooled down I checked the radiator which was missing about 1/2 a gallon. I found a small leak on the lower radiator hose and. My question is why didn't the water from the overflow go into the radiator when it went low? I check the overflow everytime I get on. I replaced the original radiator cap with one from NAPA which was rated at 7lbs. Do I have to prime the hose that goes from the overflow bottle for this to work? Do I need a special radiator cap?

[mark777]

1700;

I would check and make sure you have a cap that has a double lip seal and also make sure your overflow bottle hose does not have a pinhole or too thin as it will collapse when warm. Other than that just a routine check of screen, 30/70 coolant mix - 70 75% water (this is critical especially on thermosiphon) and so on.

*****edit***** Totally missed the sentence about the hole in your lower hose....sorry as that whould create most of your problem.*****

Hope this is some help. Regards, Mark

[normde2001]

The hose leak would prevent the system from creating the vacuum needed to draw the coolant back into the radiator as it cooled down.

[Inspector507]

Maybe enough leaked out of the lower hose that the water never had a chance to expand far enough to reach the overflow bottle?

[1danny]

The radiator cap should be 13lb. I have the Yanmar caps in stock if you need one.
Danny
Parker Equipment Co

[normde2001]

Danny, I keep hearing about 7 lb. caps from time to time. Do some Yanmars require 7 lb. caps, or is that just what some Japanese farmer happened to have handy?

[fig]

1700

I am not sure what temperature my 1700 would see before I installed gauges, but 170 to 210 sounds normal (depending on what you are doing). While mowing with a 5' finish mower, mine will run around 190 and when I get to the thick grass were it might lug for a second or two, it will jump up to 200-210. I have also found that the pitch (right or left) and what gear I mow in (lower in 2nd/hi and higher in 3rd/hi) will make a difference in the termperature as well. I had a post here in the past and was told the "idiot light" will come on around 235 (pretty sure that's what I was told).
Like Mark said above: I check the screen and radiator fins to make sure they are not clogged and check the water level every time I use the tractor. It has become habit; just like checking the motor oil.

[Yanmar_1700]

On the "Double Lip Seal". What would that be? Do you know a NAPA equivelent. By looking at my Rad Cap, what should it look like? I have read that I need a 7lb cap. What is the "lb" in reference to? I have been using straight distilled water with "Water Wetter" from Redline. Four capfulls per quart. Makes the water a pink color. No antifreeze.

[mark777]

1700,
under your cap you should see one solid rubber seal, and under that one you should see one more........lbs represent the amount it takes for back pressure before it will vent . I have yet to try the water wetter, but heard it works well, so you should be fine on the coolant part. Down here I use 20/80 on thermosiphon and 30/70 on water pump models, but it seldom get in the teens.

regards, Mark

[1danny]

I'm not sure Norm, I think most are 13lb.
Danny
Parker Equipment Co