Replacement rubber boot for oil pressure switch

[Old Guy]

Back in September I changed out my coolant hoses. When I did the oil cooler hoses I noticed the rubber boot over the oil pressure switch was kind of crunchy. In fact it partially cracked as I was moving stuff around. I cleaned it up and taped it up with some silicone self amalgamating tape; but, it really needs replacement if I am going to have any chance of wining the NSX Concours d' Elegance. I checked and the rubber boot is not part of the oil pressure switch. My guess is that it might be part of the wiring harness. If that is correct I am definitely not purchasing an engine harness just to get a new OEM boot.

There do appear to be some boots that might work. Unfortunately, non are available locally so it is order, test to fit, order another one if it doesn't work out, repeat. I was wondering whether anybody has a line on a 'this boot fits perfectly and is available for the same price as a venti latte from Starbucks'?

 

[bullithollywood]

The oil pressure switch boot off a Honda Shadow VT7XX motorcycle looks like it can work.

2001-2007 Honda VT750 Shadow 750 Spirit Engine Oil Pressure Sensor & Sub Harness

Compatible Vehicles Submodel Year Make Model VT750C2 2007 Honda Shadow Spirit 750 VT750DC 2007 Honda Shadow Spirit 750 VT750DC 2006 Honda Shadow Spirit 750 VT750DC 2005 Honda Shadow Spirit 750 VT750DC 2003 Honda Shadow Spirit 750 VT750DC 2002 Honda Shadow Spirit 750 VT750DC 2001 Honda Shadow...

c3cycle.com

 

[Old Guy]

That looks like a possibility. I may have to cruise by the local Honda MC dealership to see what a new one costs and whether I can get eyeballs on the piece to see if the size looks correct.

 

[bullithollywood]

I have a 95% confidence it’ll fit, the Shadow sensor appears to be wi a couple mm dia of the NSX’s. Ive ordered a used one myself to keep in reserve. Rubber parts are the things that will just go away over time.

 

[Old Guy]

When you get it, post the details on the wire termination at the switch. The NSX oil pressure switch uses a screw lug terminal. The Shadow switch looks like the wire is sealed where it enters the boot which means it will have to be spliced in rather than feed the existing wire into the boot. If the shadow does not use a ring terminal at the switch that could make fitting the boot more complicated.

 

[bullithollywood]

When you get it, post the details on the wire termination at the switch. The NSX oil pressure switch uses a screw lug terminal. The Shadow switch looks like the wire is sealed where it enters the boot which means it will have to be spliced in rather than feed the existing wire into the boot. If the shadow does not use a ring terminal at the switch that could make fitting the boot more complicated.

Uses a ring for lug screw just like the NSX. Of course you will have to cut the wire and replace or reterminate the ring. Looks like a perfect fit.

 

[Old Guy]

It looks like you can purchase just the wire harness with boot / no pressure switch. The part number is 32101-MCL-000. I can find it on line sold new for about $10 - 15 US$. I just need to find a vendor that will ship to Canada (most will not) and for a reasonable price. Speed Supplies listed it for a nudge over $10; but, wanted $71.25 to ship it. I may have to check out the local dealer if I can't find a more reasonable delivered cost.

 

[Old Guy]

A trip to the local Honda shop indicates that as far as Honda Powersports Canada is concerned, 32101-MCL-000 is out of production. Some vendors in the US indicated NLA; however, Partzilla showed it as available and just updated that it should ship on May 1. Assuming this is all true, we should find out in a week or two whether this fits.

The new part from Partzilla was reasonably priced (12 US$) which is about the same price as used on EBay. As per normal, shipping costs more than the part does.

 

[bullithollywood]

If its the same as the Shadow cycle sensor boot it should fit perfectly.

 

[Old Guy]

Done!

This is 32101-MCL-000 which I think is called sub harness A for a Honda 750 Shadow.


The oil pressure switch boot on the end is not an exact replica of the NSX boot (on the left); but, it fits just fine with a little silicone grease to slip on the switch. It is definitely tighter than the NSX boot; but, the NSX boot has seen 24 years of use and is split in a couple of spots and getting kind of crunchy. When the NSX boot was new, it might have been exactly the same as the Shadow boot in terms of fit.


The sleeve around the wire to the pressure switch was rather hard, bordering on brittle at the end near the switch so I cut back about 13-15 cm of the sleeve to expose the wire for crimping the new boot on.


I used a closed barrel crimp for #22 wire and applied a heat shrink sleeve. I kept the length of the wire as per OEM. The oil filter is right next to the engine crankshaft pulley and you don't need extra wire getting caught up in stuff. I used this stuff for the sleeve in 0.17" size

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Its nice because it is chemical and heat resistant. I cut it a little longer than the piece of the sleeve I removed. It fits nicely inside the remains of the cut back OEM sleeve for some overlap.



I installed the sleeve first and shoved it just about all the way into the remains of the OEM sleeve before I did the crimp. Then I pulled the sleeve back out to cover the wire. I did not heat shrink the new sleeve to the original sleeve or to the boot. Having the sleeve loose and free to move made pushing the boot back along the wire to connect the terminal much easier and will make future removal much easier .

All done with the P clamp back in place. The new sleeve extends all the way through the P Clamp and about 1/2 way across the top of the oil filter pedestal.



As noted, Honda Canada no longer lists the part as available so I got the brand new harness from Partzilla for $11.99 US$. Unfortunately, the shipping was $15 and with the currency difference and bank currency fees made for about $37 Cdn - for a rubber boot. If you are in the US and Honda USA still has the part available via your local MC dealership that would make for a much more reasonable cost.