Heater hose leaking

[Yousef]

Hey y'all,

 

What type of heater hose do you use for a 620?  Do you use 1/2" inside diameter, or 5/8"?  What type of clamps do you use?

 

I had a leak at the end of one my heater hoses.  The hose was a 3/4" inside diameter and may have been installed by previous owner.  I went ahead and replaced it with a 5/8", and got new worm clamps.  However the leak is still there.  I've wiped down both the nipple and inside the hose, as well as tightened the clamp very tight.

 

I'm wondering what you all use in this situation.

 

Thanks!

 

Yousef

[datzenmike]

At the heater core and valve? or at the fitting on the head or the return line to the lower rad hose fitting??? The steel fitting on the head can corrode away, I've replaced them before. 

 

Strikes me that 3/4" is too large. A gear (hose) clamp can probably seal it but it looks bad and simply isn't right.

 

If at the lower rad return hose it might be the smaller by pass hose leaking above it

[DanielC]

The smaller hoses on the engine are 9/16, or it's close metric equivalent, 14MM.   I have a good local auto parts store that had been an independent auto parts store since 1934.  They have let me go in to their "long term" storage area where they have lots of obsolete and rarely sold hoses, and just look for the hose I need.

Some of them may still be available from a Nissan dealer. 

Use this website to get Nissan part numbers.

https://www.carpartsmanual.com/#ManualsMenu

[Yousef]

It seems to be actually coming from the heater cock control valve...I see that it is part number 27017-B5000.  But it looks like this part is discontinued...I wonder if I can find a similar part?

[Yousef]

Any similar valves from other Datsuns?

[datzenmike]

 The later '83 and up 720 uses an inline plastic valve.

 

[Yousef]

I wonder if I can use an aftermarket one from the autoparts store...another idea is to bypass the valve for now, but that would mean constant heat.

[banzai510(hainz)]

Constant heat is OK and just use your vent to keep it cool inside if needed. Not that a old heater is really that hot.

On my 521 I keep the valve ON to keep it from wearing out as its so old. I just use the vent flaps

[datzenmike]

As long as it's flowing through the heater core you can skip the valve and leave on.  Do not bypass the heater core by connecting the two hoses, seal them off with large bolts in the ends with gear clamps.

[bananahamuck]

Try fixing it,,, it costs about $2. in O rings from the hardware store

 

Read this ,, it worked for me. 

 

 

 

Before you say "but bananahamuck ,, that is a 510 valve and i have a 620""    Weeeell here you go .. Another how-to ,, using a 620 valve to fix a 510 valve with many pictures to show the similaries of the two valves

 

http://www.510coop.com/heater/

 

 

 

 

 

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[Yousef]

Thanks everyone!  Not sure what I'm gonna do yet, but leaning towards bypassing

[datzenmike]

6 hours ago, datzenmike said:

As long as it's flowing through the heater core you can skip the valve and leave on.  Do not bypass the heater core by connecting the two hoses, seal them off with large bolts in the ends with gear clamps.

 

Plug the hose ends just like the heater does when shut off. Otherwise the hot water is passed right back into the block without any cooling whatever. This is the same as taking 1/4 of your top rad hose water and by passing the rad and running it straight back into the engine. It only makes the rad's job harder.