Question about coolant hose.

[klmken]

Good morning, replacing coolant hoses and received the one with the clamps in the picture and the old hose without the clamps and they look nothing alike when I check suppliers the pictures do look the same for the new part I was sent. Can someone confirm that this is the correct part? Trying to get it on is tough... It's the 506 hose between the motor and the rear firewall.

 

[Old Guy]

First off, the hoses are a bugger to get back on the fittings. I slathered the insides of the hoses with a lot of silicone grease. I used Silicone dielectric grease because I had it on hand. The silicone grease for pool pumps and dry suit zippers will also do just fine. Even with the grease it takes a lot of shoving.

My recollection is that the hose has a painted dot on it which determines the orientation. My recollection is that the dot is towards the engine - maybe somebody else can confirm that. On a lot of the hoses the orientation is obvious. On the two big hoses on the firewall the orientation is not so obvious; but, having it oriented incorrectly is going to make fitting a problem.

My recollection is that 19506 and 19507 (the other big firewall hose) are similar. Is there any chance that you have mixed them up? When I removed my hoses I paired up the old hose with the new hose and left the new hose in its package until it was time to do the install. Heat will cause the rubber in those hoses to take a set so when they come off they no longer look exactly like the replacements.

If there is no chance that you have mixed up the two hoses then make sure the dot orientation is correct and use lots of grease.

 

[klmken]

bugger may be an understatement! I've been baking the bastards @ 250 in my oven and finally got the passenger side on and the dirver side halfway before I ran out of warmth and light. Coius amonts of spray cooking oil as well. You hit the nail on the head with the hoses being swapped now I am left to figure orientation as my dot is gone or wasn't there...

 

[Honcho]

It looks like the top hose in your picture is 507. 507 should go to the thermostat cover and, as Old Guy mentioned, the dot should face the engine. On my new hoses above, it was a yellow dot.

506 should connect to the water jacket and has a white dot on mine. As mentioned, use a good amount of silicone grease. They are a tight fit.

 

[ekhonda87]

I echo previous comments. Never in my life would I have imagined a coolant hose being so hard to install. Had to come back to it the next day after taking a breather.

 

[klmken]

View attachment 187069

It looks like the top hose in your picture is 507. 507 should go to the thermostat cover and, as Old Guy mentioned, the dot should face the engine. On my new hoses above, it was a yellow dot.

506 should connect to the water jacket and has a white dot on mine. As mentioned, use a good amount of silicone grease. They are a tight fit.

I wonder if the writing on the hoses is always in the same spot? My 506 hose has the writing facing up and a small kink close to the engine. when I look at the old hose it looks like I have it in backwards currently. I figure I'll get the motor started on distilled water so I can get it warm as I couldn't remove it in the 40 degree weather today to turn it around.

 

[Old Guy]

Looking at your photo and looking at Honcho's picture I am thinking that you might have the 506 and 507 hoses mixed.

Rather than mess around experimenting disconnecting and reconnecting things, the better way to address the uncertainty might be to purchase one new hose, either 506 or 507. The new hose will have the dot and by comparison you should be able to confirm which of your existing hoses is which and you should be able to determination the correct orientation on at least one hose by using the dot on the hose in the package.

One new hose is only about $45 from the dealership. If you leave the hose in the undamaged package you might be able to return it to the dealership. From my perspective you have spent too much effort messing around. Just fork over the $45 or $90 (for both hoses), don't mix up the hoses during assembly and align the dots and you should be good.

Heating the hoses in an oven does not strike me as a good idea. The air temperature isn't the issue. I would be concerned about what the exposure to the radiant energy from the element might be doing to the rubber surface (the equivalent of browning the outside of your bran muffins). If you want to pre heat the hoses a hot air gun or immersion in a bucket of hot water would be a better solution. Cooking spray would not be my choice for a lubricant. I suppose it is vegetable based so probably won't damage the rubber; but, I really don't how well it will stay in place during assembly. Silicone grease (not spray) is the go-to for a reason. It is rubber friendly and will even when it is pushed off the rubber during assembly the rubber remains slippery facilitating assembly.

 

[Old Guy]

I echo previous comments. Never in my life would I have imagined a coolant hose being so hard to install. Had to come back to it the next day after taking a breather.

You haven't experienced the most miserable hose in the world to re install until you have done the lower rad hose on the 1997+ NSX. The firewall hoses are just awkward to work on and shove into place. The 1997 + lower rad hose is close to; but, not 100% impossible if you are stubborn, to fit without removing the radiator.

 

[klmken]

Looking at your photo and looking at Honcho's picture I am thinking that you might have the 506 and 507 hoses mixed.

Rather than mess around experimenting disconnecting and reconnecting things, the better way to address the uncertainty might be to purchase one new hose, either 506 or 507. The new hose will have the dot and by comparison you should be able to confirm which of your existing hoses is which and you should be able to determination the correct orientation on at least one hose by using the dot on the hose in the package.

One new hose is only about $45 from the dealership. If you leave the hose in the undamaged package you might be able to return it to the dealership. From my perspective you have spent too much effort messing around. Just fork over the $45 or $90 (for both hoses), don't mix up the hoses during assembly and align the dots and you should be good.

Heating the hoses in an oven does not strike me as a good idea. The air temperature isn't the issue. I would be concerned about what the exposure to the radiant energy from the element might be doing to the rubber surface (the equivalent of browning the outside of your bran muffins). If you want to pre heat the hoses a hot air gun or immersion in a bucket of hot water would be a better solution. Cooking spray would not be my choice for a lubricant. I suppose it is vegetable based so probably won't damage the rubber; but, I really don't how well it will stay in place during assembly. Silicone grease (not spray) is the go-to for a reason. It is rubber friendly and will even when it is pushed off the rubber during assembly the rubber remains slippery facilitating assembly.

I did indeed have them reversed. I wrapped in foil so radiant wasn't an issue. I'll have to get some silicon as I finally got both hoses on but the inner hose must be clocked wrong as it is slightly kinked. Need to wait for some warmth to remove and replace. Thanks for the guidance!