Another Coolant Hose Replacement Thread

I am changing out my coolant hoses...22 of them. I will post my observations and any hints and tips I come up with as the job moves on. In that spirit, here is my first tip: I found "Radiator Hose Grease" at Auto Zone. The stuff comes in small packets for a buck per packet and works wonderfully when applied to the inside of the hose section and the outside of the hard line. Also helps lubricate the oem hose clamps that have to be forced over the bib bulge on the hardline in hard to get to places. A little goes a long way. Three packets are probably enough to do a full set of hoses.

Now I have a question...

Where are hoses 10 and 11 below located. Looks to me like they are on the passanger compartment side of the front bulkhead. If so, how hard are they to get to?

There is no 21 or 22 on that parts list.

I know what your talking about but you posted the wrong diagram. LOL

there are 2 diagrams for the coolant hoses.

its the other page

I have it posted on my 2004 build page 13-14 I forget

good luck on it mike! i just drop my car off this weekend to get the same thing done.

Briank said:

There is no 21 or 22 on that parts list.

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Musta been the coolant fumes getting to me. I meant parts 10 and 11. Original post corrected. Thanks for pointing out my goof.

shawn110975 said:

I know what your talking about but you posted the wrong diagram. LOL

there are 2 diagrams for the coolant hoses.

its the other page

I have it posted on my 2004 build page 13-14 I forget

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Right diagram. Wrong numbers. (See above.) Yeah, I have hard copies of ALL THREE diagrams sitting next to my car in the garage. (the one above, the full car cooling hose diagram and the oil cooler hose diagram)

Thanks for posting, though. It got me looking at your 92 bb build thread which, might I add, looks fantastic.

#10 is under the car in the tunnel.

#11 is in the engine bay under the coolant tank

Regards,
LarryB

Larry Bastanza said:

#10 is under the car in the tunnel.

#11 is in the engine bay under the coolant tank

Regards,
LarryB

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I was hoping you would chime in, Larry. But this is what has me concerned...The diagram in my op is for the WATER VALVE. This is the parts diagram for RADIATOR HOSE:


Part 10 is listed as 79727-SL0-A00 in the WATER VALVE parts diagram. The straight connector hose under the car is listed in the Parts Diagram for RADIATOR HOSE as 19519-PR7-A00.

Part 11 is listed as 79728-SL0-A00 in the WATER VALVE parts diagram. The similarly shaped part under the coolant bottle in the radiator hose diagram is listed as 19506-PR7-A01.

Sometimes it is just best to get your butt under the car and see it for yourself.

If you look at your bottom drawing there are TWO hoses, #17 and #18. Also in the tunnel is #10, since that hose brings the water to the water valve for the heater core.

There are another two hoses #11 and #12 in your bottom drawing, they are under the coolant tank ALONG WITH #11 you originally asked about.

So water comes from the block, through #11 you asked about, through #10, you asked about into the water valve.

#11 and #12 and #17 and #18 carry coolant to/from the radiator, #11/12 under the coolant tank, #17/18 in the tunnel.

So there are THREE coolant lines that run front to back in the tunnel.

Now go take the tunnel cover off and get the coolant tank out and give it a look see.

HTH,
LarryB

Yup...now that makes sense...lot more sense than the heater valve diagram, too.

Actually I got NOTHING done yesterday. Too sore from working on Saturday when I only managed to get all the hoses out of the front trunk (and a few back on.) Of course I pulled the sapre tire, mount, battery, and radiator (to clean it up),and in the engine bay the coolant tank, and intake (and a couple of hoses there). Being 62 and not stretching first, the backs of my legs were pretty sore Sunday. I'll be puttering with it tonight and evenings this week but I probably won't get under the car until next weekend. That's when I plan to do all the oil cooler hoses and the center hoses under the hose cover. Really looking forward to working on my back rather than bending over and reaching.

Thanks for clearing things up, LB. You're the best.

Another LarryB tip that helped me out with the hoses- if you have a pool supply store nearby, get a tube of silicone hose lube. It works great on getting the hoses on the fittings and will make taking them off again much easier. I used it when I replaced my coolant bottle and it worked great.

I saw LB's post in that thread, Honcho. Good tip. I'm hoping the "Radiator Hose Grease" I got at a nearby Auto Zone will do the same trick. It certainly makes the hoses go on way easier and getting one off was easy too. (Don't ask.) Hopefully it will last for the many years between hose jobs.

The key point to the lube is it cannot be petroleum based.

That will ruin the hose.

Regards,
LarryB

I have a few questions about this maintenance task. I have a 91 and I have purchased the complete hose kit.

1) My car has the green fluid in it right now (that is what it had in it when I bought the car). Is there a way to to completly drain and flush this green stuff out and make sure it is all out before adding the new blue stuff in? Should I maybe take it to the dealer and get a fluid drain and flush prior to replacing the hoses, so that I am starting with a clean(ish) system?

2) How much fluid should I buy when it comes time to refill after I have replaced all the hoses?

Any other hints/tips/videos/step-by-step would be appreciated.

Dwayne

Larry Bastanza said:

The key point to the lube is it cannot be petroleum based.

That will ruin the hose.

Regards,
LarryB

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The stuff I found looks like petroleum jelley but it is made for radiator hoses. So one would hope it is not a petro product. But I will be reading the label a bit more carefully this evening. Thanks again Larry.

DeVinci13 said:

I have a few questions about this maintenance task. I have a 91 and I have purchased the complete hose kit.

1) My car has the green fluid in it right now (that is what it had in it when I bought the car). Is there a way to to completly drain and flush this green stuff out and make sure it is all out before adding the new blue stuff in? Should I maybe take it to the dealer and get a fluid drain and flush prior to replacing the hoses, so that I am starting with a clean(ish) system?

2) How much fluid should I buy when it comes time to refill after I have replaced all the hoses?

Any other hints/tips/videos/step-by-step would be appreciated.

Dwayne

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Hopefully others will weigh in on ths as I have the same issue. My coolant is also green, and is also what was in the car when I purchased it. The coolant was replaced when the water pump was replaced by a reputable Dallas Honda/Acura service specialist shop (Hondacura) so I would hope it is just the older green version of Honda's best. But I am replacing mine anyway.

Using the block drains will get you pretty close. However they are clogged 1/2 of the time, especially on cars that have not had coolant changes in a while.

So if you open them up and they do not flow, remove the outer piece, then use a pick or a short piece of wire hanger to unclog them. Remember to keep your face out of the way.

Also drain the radiator completely, and open the two drains in the tunnel. The service manual has a good description/pics of this.

HTH,
LarryB

Larry Bastanza said:

The key point to the lube is it cannot be petroleum based.

That will ruin the hose.

Regards,
LarryB

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How about some hand soap or dish washer?

nis350 said:

How about some hand soap or dish washer?

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Not sure I want my coolant contaminated with a foaming agent. Pretty hard to get the hoses back onto the hard lines without getting a bit of the lube on the inside of the hard lines. Just a thought.

I'm heading over to a marine supply store that's just a couple blocks from work to see if they have silicon grease. I'm not sure I trust the stuff in a pouch from Auto Zone.

Front: Done
Engine bay: Done

Tips:
A lot of the coolant hoses around and to the throttle body/water pump are showin in the "Oil Cooler Hose" diagram in the official Acura parts diagras like this one. Don't be fooled.



Not every hose looks exactly like the diagram. Sometimes the diagram will illustrate a hose as being longer than it actually is so the ends will line up with the hard lines or in the diagram. Sometimes the hose will even be a different shape! (I only ran into this once...a hose that was pictured as straight actually had a significant bend in it.

Don't be shy about pulling parts off if they are in the way. Four bolts, a couple of connectors and some coolant hoses will get the throttle body out of the way. Ditto for that vaccum hose distribution bracket that is on top of the throttle body.

It's nice when you can replace one hose at a time...makes positioning the new hose correctly a snap. But you can't do that most of the time in the NSX...too many hoses in the way of other hoses. If you have a good mechanical memory it shouldn't be a problem. Just keep the parts diagrams handy. But if you tend to forget how things were arranged, take pics as you go. You won't really have any problem getting each hose on the right hard lines or reconnecting the various electrical connections you have to unplug. But it isn't that hard to mount a hose backwards. (I only did this once and eventually it became obvious). Or you might find a hose is not oriented correctly and you have to unclamp it to striaghten it out and other stuff you have already reinstalled is in the way. (I didn't have that problem but I could see how easily it could happen.)

Take your time. This advice appears in almost every coolant hose thread and I can't emphasize it enough. It's about 100 in the garage and worse in the sun this weekend so I only worked for about 15-30 minutes between long water breaks. Things always went smoother right after a break than toward the end of a long work session. If a clamp or hose was giving me trouble, I would take a break. Afterwards the same job was easy.

Replacing all those coolant hoses is really a pretty easy job but its easy to mess up or do damage if you hurry or get impatient.

Next weekend I will take care of the five hoses under the car. (I hope there's only five 'cause that's all the new parts I have left.)

Wow...Mr. Natural. Haven't seen him in Years!

BATMANs said:

http://www.scienceofspeed.com/products/engine_performance_products/NSX/Venair/coolant_hose_kit/

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Ahhh...BATMANs has posted. Now this thread is complete!

I considered silicone main hoses but decided to go with OEM. If I tracked the car regularly I probably would have gone with the SOS hoses.

The last OEM hose set held up pretty well for 20 years. Twenty years from now the current set will likely be someone elses problem.

tof said:

It's nice when you can replace one hose at a time...makes positioning the new hose correctly a snap.

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IIRC from when I did my hoses, the new ones have a mark, an arrowhead I think, that indicates which end faces toward the engine. Some of the hoses are so subtly shaped that it's tough to tell at first glance which way they go on, so referring to this mark can be helpful in confirming you have it right.

Russ said:

IIRC from when I did my hoses, the new ones have a mark, an arrowhead I think, that indicates which end faces toward the engine. Some of the hoses are so subtly shaped that it's tough to tell at first glance which way they go on, so referring to this mark can be helpful in confirming you have it right.

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They typically have a white or yellow dot on one end to orient them. (yellow on only one hose, the middle one in the engine bay IIRC, so you cannot mix the two up).

Regards,
LarryB