l20b Small "L" Coolant Hose

[serum114]

I am trying to identify and replace a small hose is the cooling system of my L20B

A part number or description of a functional replacement would be great!

 

[datzenmike]

It's part of the coolant by pass system that eliminates cold stagnant coolant caught around the thermostat. The lower hose part numbers are...

14056-23001 for most L16/18

14056-U6700 for '75-'77 L20B without intake coolant

14056-N5800 for '78-'80 L20B with intake coolant.

 

These are pre formed bend hoses but as far as I can see anything that fits will work.  (I think the diameter is 9.5mm or 3/8"? this is, I think, the hole size)

[serum114]

Thanks Mike, your the best!

I've tried just getting a small bent hose but the ends needed to be different diameters.

Hopefully I can track one of these down: 14056-N5800

[MikeRL411]

SURPRISINGY, A 1970 bUICK 455 ci THERMOSTAT BYPASS HOSE SEEMS TAKE CARE OF THESE "PROBLEMS" SOMETIMES WITH CAREFUL CUTTING OF THE EXTRA LONGTH OFTHE BUICK PART NUMBER!

[DanielC]

I believe the 90 degree hose, between the water pump inlet, by the alternator on a L16 is A4056-23001, and I was able to order and get it from a Nissan dealer.

[Rays74]

Nissan OEm is best but I have used this aftermarket hose for quite a while on the L motors........cut it down and it fits like a glove AND you can also use the leftover pieces to replace the little section at the manifold below the carb :D 

 

http://www.amazon.com/Dayco-87000-Heater-Hose/dp/B000C0YQDA

[datsunaholic]

The issue I've had with non-Nissan hoses is that the original hose is different diameters on each end, so normal hoses don't fit right at all.  I've always been able to get them through the Dealer, but it's been a few years since I ordered any.

[Rays74]

Agreed, this hose is a single size but it works 100%. I had no trouble getting it to stretch just a bit over the nipple at the water inlet and it slipped onto the metal transfer pipe like OEM. It fit the nipple under the carb same way.

:D

[ducky]

Howdy gents. Ran into the same problem as OP while I'm trying to get my cooling system replaced.

 

The last owner or someone swapped the correct hose for like a 1/2 elbow with a 3/8 sleeve shoved into it on one side. And the dreaded worm clamps of course.

 

Here's a picture of me trying to get the dayco hose on above. Part number will come up as B87000 of you can't find it with just the numbers.

 

I'm not happy with it and will continue to look for the proper hose. Preferably not having to come from Australia with $70 shipping.

 

Edited May 20, 2022 by ducky

[datzenmike]

I think the original hose is larger on the cast fitting than the metal pipe end and why it's a bitch yo get on..

[Stoffregen Motorsports]

Here's a PDF from Napa for their cooling hoses. It starts at small diameter and works it's way up from there. Measurements and pics (crappy pics) help choose the right hose. I use this guide regularly. The only problem is that Napa guards their part numbers hardcore, so cross referencing to other brands is impossible.

 

https://www.napabeltshose.com/~/media/napa/flyers/molded-coolant-hose-id-guide_napa-interchange-final_lr.pdf

[Figbuck]

Here is how I deal with these factory bent coolant hoses.  I get high quality Gates hoses by the foot. I went to the hardware store plumbing section for brass PEX water supply fittings. For that little by-pass hose I use a short piece of 1/2" tubing and 3/8" hose with a 90 degree Ell reducer fitting...  half to three-eights... male with barbed ends. They are four bucks, plus four high quality hose clamps. Same with heater hoses only 5/8" Ell 90 with male barbs. Pretty easy and bullet-proof with Gates hoses.

[ducky]

I notice I never came back to fill anyone in on this. I found the hose. It's a Gates 18217.

 

[banzai510(hainz)]

11 hours ago, ducky said:

It's a Gates 18217.

thats good ro know,

 

Zcar Depot has that water intake w/o the upper outlet in case one doesnt need the water line to intake(sidedraft set ups)

[ducky]

10 hours ago, banzai510(hainz) said:

thats good ro know,

 

Zcar Depot has that water intake w/o the upper outlet in case one doesnt need the water line to intake(sidedraft set ups)

 

isnt that the water pump bypass and has nothing to do with the carb? it goes directly to the thermostat housing

[datzenmike]

It's the thermostat by pass. It forces circulation of coolant from inside the engine past the thermostat. Without it the water around the thermostat is stagnant and remains cold while the internal coolant gets hot and over heats. With it the thermostat reacts much faster to actual engine temperatures. Early L16s didn't have this and relied on a 'jiggle' valve in the thermostat to pass coolant into the radiator but this displaces cold water from the radiator into the engine whereas the by pas returns it directly to the engine by passing the radiator.

 

All other L4 engines but the '75-'77 L20B had coolant flow out of the head and through the intake runners. This coolant was plumbed into the by pass also. 

[banzai510(hainz)]

it heats the intake manifold and hole on the side of the head flow the warm water in to it so the carb dont freeze in winter.

 

later L20 had no water line as it had a exhaust manifold bolted to the carb intake. I usually dont see these much. as later L20 went back to the water heated type

 

one of my cars had a bypass( a U shaped hose ) to the stat housing and one didnt but still wen to the intalke

Edited March 25, 2023 by banzai510(hainz)