Water pump bolt thread sealant

[Old Guy]

I was planning to reuse the existing bolts when I replace my water pump when I eventually get around to doing my coolant hose and TB replacement. The new bolts come with a dry sealant and I recall threads on the subject referring to applying sealant when reusing the bolts. What have owners used as a replacement sealant (don't say Hondabond HT)?

 

[goldNSX]

There's no 'sealant' needed. Nothing can be seeping from the bolts. No coolant or oil behind them. The red stuff is like locktite, so locktite blue would do it too I guess.

Those bolts are special in the way that they break their head if you try to overtorque them like 22 Nm on a 10 mm by error. Don't ask me how I know. At least it protects the head. If you have to use too much torque next time this might happen, so being $20 too cheap is not the way to go. Just my 0.02.

 

[Honcho]

I was planning to reuse the existing bolts when I replace my water pump when I eventually get around to doing my coolant hose and TB replacement. The new bolts come with a dry sealant and I recall threads on the subject referring to applying sealant when reusing the bolts. What have owners used as a replacement sealant (don't say Hondabond HT)?

Most replace with new, but Hondabond HT is what dealer techs use if you re-use the old ones. Run the bolt threads on a wire brush and run a thread chase (not a tap- it may cut the aluminum and weaken the threads) into the block to clean out the old sealant. Put a light amount of HB on the bolts at a length close to the OEM red sealant. Rather than do all that (except the thread chase- you have to do that regardless of whether you re-use the bolts), I just buy new bolts.

I think Gold is right- I've studied the components and I just can't see a way where the bolts seal against coolant flow. I suspect instead, like Gold, that the compound is a thread-locker. The water pump position and tension is critical to the timing belt on the NSX, so Honda likely adds the locking compound to ensure that the bolts do not loosen and back out, which could cause major engine damage if the pump (and its pulley) move out of position. Thus, instead of Hondabond, you could try blue loctite.

 

[Old Guy]

Hondabond HT baffles me because it is silicone based gasket stuff. Not the hot ticket for threads. I can see using a thread locking compound.

 

[MotorMouth93]

There seems to be a bit of confusion about what the purpose of the sealant is, my understanding is that it's not to lock the threads, it's to prevent potential coolant leaks from corroding and seizing the bolts into the block, and for this purpose Hondabond HT works just fine.

I experienced first hand why this is important on my BMW M62 V8 a year or so ago, there is this super fun coolant passage cover plate on the back of the block behind the flywheel that comes with a crappy paper gasket that invariably starts seeping after 100-120k miles. The seeping coolant then causes the 17 separate M6 bolts to fuse into the block. Sometimes they come out, sometimes they need to be drilled out, and if you're a dumbass like me, you snap off a bolt extractor in the block "because that bolt totally started to turn before it broke", then have to take the whole motor to a machine shop and pay them to remove it for you. (fortunately the motor was already out of the car)

 

[Old Guy]

I am iffy about the corrosion thing. If you wanted to avoid galvanic corrosion between the steel bolt and the aluminum block I would think that a dacrotized bolt might be the preferred protection method. Plus, properly maintained coolant (and we know everybody does that) has corrosion inhibitors to reduce this nastiness. In an aluminum block galvanic corrosion should result in the aluminum buying the farm and the bolts being mostly OK. Also, Honda does not use this coating on the thermostat housing which wold seem to have similar risks so I am not so sold on that idea. If I wanted to deal with the corrosion issue I would be more inclined to slather on a good coating of my favourite anti seize goop

After a little checking I found that I can get the 7 - 6mm and 2 - 8 mm bolts from Amayama for around $11 US. That is like two venti cappuccinos plus a gratuity so I think I will just add them on to my next Amayama order and stop wondering is it a sealant, locking compound or anti seize. Plus it gives me a perfect excuse to further procrastinate on doing my maintenance.

 

[goldNSX]

Potential corrosion could be a problem too like preventing the bolt coming loose. A locktite also is also some sort or sealant as well esp. when using it as a fluid. But again, $20 ...

 

[sylcurt]

I am in that spot right now and will definitely go the new bolt route....

I've also been searching to find the actual part numbers of the bolts and how many of each are needed...do you know off hand when referring to the attached schematic how many of each are needed...I am challenged to find which 9 total bolts, unless they are essentially all different...but maybe there are some assumptions of needing more and just not shown. If you can shoot me a PM or even in this post , a reply on how many of each are needed based on the diagram (ex:2 of #14 , 2 of #20 , 3 of #21 , etc) that would be a big help and I can add it to my order. Thank you.

View attachment 165592

 

[Honcho]

I am in that spot right now and will definitely go the new bolt route....

I've also been searching to find the actual part numbers of the bolts and how many of each are needed...do you know off hand when referring to the attached schematic how many of each are needed...I am challenged to find which 9 total bolts, unless they are essentially all different...but maybe there are some assumptions of needing more and just not shown. If you can shoot me a PM or even in this post , a reply on how many of each are needed based on the diagram (ex:2 of #14 , 2 of #20 , 3 of #21 , etc) that would be a big help and I can add it to my order. Thank you.

View attachment 165592

From my master spreadsheet:

Water Pump Bolts (special) 90049-PH7-000 (2 pcs)
Water Pump Bolts (special) 90052-PH7-000 (7 pcs)

 

[ralph cerbone]

Guys take it easy about the red sealant . Did you ever think it might be a thread release compound .

 

[sylcurt]

Many thanks Honcho, that was exactly what I was looking for !:smile:

 

[Miner]

Like anti-seize?

 

[ralph cerbone]

Like anti-seize?

Yes but a lot less of a mess than anti seize , no guess about how much to apply, perfect for production use , I might be wrong but it makes sense . Maybe Kaz could shed some light .

 

[tucsonsx]

Yes but a lot less of a mess than anti seize , no guess about how much to apply, perfect for production use , I might be wrong but it makes sense . Maybe Kaz could shed some light .

That sure makes sense to me - and, since anti-seize compound increase the torque required for the same level of tightness compared to a dry bolt, the blue coating on the bolts might allow for a more predictable and lower torque setting when tightening the bolts.

 

[ralph cerbone]

Thats pretty much my thought , I spoke to a friend who happens to be a honda engineer , he responded "only you would come with that question " . He is a suspension engineer but will check it out .

 

[Old Guy]

That sure makes sense to me - and, since anti-seize compound increase the torque required for the same level of tightness compared to a dry bolt,

No, anti seize acts as a lubricant on the threads which reduces the torque that must be applied to the bolt to obtain the same clamping force (bolt extension). The NSX service manual specifies that the spark plugs are to be installed with anti seize applied to the threads and torqued to 13 ft-lb. This is less than what NGK / Denso recommend as the tightening torque for the same plugs when installed dry. Permatex has (or at least used to have) application information for their anti seize products on their web site. One of those guides provides a reduction in tightening torque (versus clean dry threads) for various bolt sizes when anti seize is applied. As a general guide, the reduction in tightening torque for bolts with anti seize applied is about 10-15% compared to a dry bolt.

Definitely do not increase your tightening torque when using anti seize.

As to what the stuff on the bolts is, I offer no opinion.

 

[tucsonsx]

You’re right - thanks for correcting that - stripped threads and sheared bolts are the worst.

 

[ralph cerbone]

Old guy is correct ,if you use anti seize you reduce torque , but when it comes to spark plugs NGK want no anti seize , the coating on the new plugs cancel the use of anti seize , I know the ser. manuals say use it but that was along time ago .

 

[Old Guy]

I am not so sold on the NGK miracle coating substitute for anti seize. Last year I replaced the NGK platinum miracle coating plugs on my 2003 Pilot and the NSX and (with the exception of one plug on the NSX) all of the plugs were a bear to get out - requiring a breaker bar. The replacement plugs went in with anti seize torqued to 13 ft-lb to avoid a repeat of that episode.

Just my hang-up!

 

[Miner]

Yes but a lot less of a mess than anti seize , no guess about how much to apply, perfect for production use , I might be wrong but it makes sense . Maybe Kaz could shed some light .

Anti Seize messy?! Who doesn’t like to ruin their shirt, pants, socks and drawers every time one opens the jar of it!

In all seriousness, even if the bolts are pre-coated with an anti seize, a bit of extra doesn’t hurt. Especially over time and exposure to the elements.

 

[ralph cerbone]

I am not so sold on the NGK miracle coating substitute for anti seize. Last year I replaced the NGK platinum miracle coating plugs on my 2003 Pilot and the NSX and (with the exception of one plug on the NSX) all of the plugs were a bear to get out - requiring a breaker bar. The replacement plugs went in with anti seize torqued to 13 ft-lb to avoid a repeat of that episode.

Just my hang-up!

If understand you the plugs where in there for 17 yrs ?

 

[ralph cerbone]

Anti Seize messy?! Who doesn’t like to ruin their shirt, pants, socks and drawers every time one opens the jar of it!

In all seriousness, even if the bolts are pre-coated with an anti seize, a bit of extra doesn’t hurt. Especially over time and exposure to the elements.

"Exposure to the elements ", thats what it is designed for , I've used anti seize for over 45 yrs . Most of the time on heavy equipment ,when i started using it was not popular in the automotive world . . Aluminum heads got popular and guys started to use , I did a lot of work on motorcycles and snowmobiles so I knew to be careful with it . I had a 2006 Yamaha 4 stoke snowmobile , the spark plugs where very thin 10 mm , some people started using anti seize on them and broke them. NGK came out with a tsb to stop ,their trivalent coating negated the use of anti seize . Do i use it, absolutely , great product ,just use it sparingly .

 

[Miner]

"Exposure to the elements ", thats what it is designed for , I've used anti seize for over 45 yrs . Most of the time on heavy equipment ,when i started using it was not popular in the automotive world . . Aluminum heads got popular and guys started to use , I did a lot of work on motorcycles and snowmobiles so I knew to be careful with it . I had a 2006 Yamaha 4 stoke snowmobile , the spark plugs where very thin 10 mm , some people started using anti seize on them and broke them. NGK came out with a tsb to stop ,their trivalent coating negated the use of anti seize . Do i use it, absolutely , great product ,just use it sparingly .

I’m with you.

I work on / with Navy ships and even a generous amount of anti-seize will be overcome by the sea air and the occasional galvanic reaction!

 

[Old Guy]

If understand you the plugs where in there for 17 yrs ?

No. According to my records the plugs in the Pilot were in for 7 years and the plugs in the NSX were 8 years.

 

[ralph cerbone]

No. According to my records the plugs in the Pilot were in for 7 years and the plugs in the NSX were 8 years.

I thought that sounded a little strange coming from you , your always on top of the situation , like I posted before I can tell "this ain"t your first rodeo " .