Water Pump Bolt to Alternator Upper Mount Bracket & belt tension adjustment

[theojo]

I replaced the water pump on my 84 back in 2007. It just recently started to leak again. I noticed when putting the new one back on that the larger bolt at the bottom which goes on last and goes over the alternator bracket doesn't cinch down tightly. About a millimeter of play in it. Is there supposed to be a washer under the bolt? Perhaps that was the reason for the leak. Obviously there has to be some play in it so that the alternator bracket will swivel to some degree when adjusting the belt, but I don't think it should be as loose as it is. Or perhaps there is crud inside the engine threads.

It just seems like a strange design for Toyota. Either the 2 bolts on either side of that larger bolt are enough to keep the water pump mounted tightly and there is no passage for coolant around the looser larger bolt or the bolt should be torqued down tightly and thereby not allow the alternator bracket to swivel at the lower end.

Any ideas?

[timsrv]

That bolt should have a lock-washer on it. The bolt should spin freely until it contacts the pump bracket, then it gets torqued to 29 ft lbs. Once torqued the bracket should not move freely. It can be moved for alignment reasons (as you have the leverage to so), but you should avoid moving it more than necessary. Once the alternator is mounted it's not a bad idea to retorque.

Your suspicions are correct (that bolt is not the right one (too long), missing the washer, or perhaps the threads on the block are messed up with crud/whatever). This is an important bolt as it applies pressure to seal a major coolant port. This is the port that passes through the block, through the timing cover, and into the water pump area. If the bolt fails to apply the required pressure you could be asking for a blown gasket between the block and the timing cover (not a fun one to replace). To get an idea of how things go together here, CLICK HERE and scroll down to the middle of that blog entry. Tim

[theojo]

Thanks Tim, I never had any idea a water pump bolt could be so significant. I'm all sealed up now with no water leaks, so I think it survived.

It turns out it was a combination of the 2. Originally the bolt bottomed out with a gap of 5/16 to the water pump. As I got the crud out at the bottom of the hole, it closed to 3/16th. That being the thickness of the bracket, I was then able to tighten it securely even before adding a washer.

I must have lost the washer the last time I changed the pump. I guess this is the only bolt on the vehicle without a captive washer! At least in the Aug. 83 manufactured group.

Now I know why the coolant in the overflow reservoir never drained back into the engine. It couldn't form a suction with that small leak.

[timsrv]

Now I know why the coolant in the overflow reservoir never drained back into the engine. It couldn't form a suction with that small leak.

Yes, I've seen this before. When the system is working correctly, during cool-down a vacuum forms and coolant is sucked from the overflow bottle. If there's a breach (leak in the system), it can suck air from the breach instead of coolant from the overflow bottle (and that really sucks). What sucks even more is ending up with an overheat condition after religiously checking the level in your overflow bottle. And that sucking action leads to a blowing action............blowing of your head gasket..........and that totally sucks . Tim

[highwind]

I cant seem to get it to tension at all. any ideas?

[highwind]

doesnt look OEM either

[highwind]

is there a write up on replacing all the belts?

[timsrv]

Don't think of yourself retarded, think of yourself as "special" (let the rest of us think of you as retarded) . Can't see everything from this picture angle, but a couple things jump out here. That adjustment bolt should have a wing-nut head (so you can adjust with your hand pressure). There is also an extra nut between the bracket and the threaded block (no call for one here). That stuff doesn't really matter much though (should still work). The real issue is having a loose belt when the adjustment is maxed out. That could only be due to a belt that's too long, having the incorrect mounting bracket(s), or having the incorrect alternator installed. The van alternator has the mounts (upper & lower bolt holes) oriented 180 deg apart. Here is a 4y engine with the correct alternator & hardware. This is where the adjustment should land with a new belt installed:



Compare with your parts to determine where the problem lies. Note: The alternator belt I'm using is Gates #K050323. Tim

[highwind]

I was surprise how easy it was to change the belts

http://vid5.photobucket.com/albums/y...psabhackmh.mp4

[timsrv]

Glad to hear it's adjusted. What ended up being the problem?

[highwind]

Glad to hear it's adjusted. What ended up being the problem?

At first I thought it was the alternator (it was from a 1985 Toyota MR2) I didnt want to wait for my CS144 so I went ahead and threw that one in.

It was most likely the belt. It was stretched or just too long.

I pulled all the belts both the ac and power steering belts were cracked in the valleys.


but now I have another problem.......

stereo wont turn on now (lol)
idle is a TAD rough but it still hangs at 1k rpm
automatic transmission doesnt want to shift on its own? (I have to let off the gas to shift?)

[timsrv]

Check your battery volts while the engine is running and somebody is holding the RPM's @ around 2k (some stereos are finicky about input voltage). You should be seeing between 13.5 - 14.75 volts here. Make sure you got all sensors hooked back up & check for trouble codes (if engine isn't running correctly transmission may not shift correctly). Tim

[NickP]

Greetings!

I recently drove a newly acquired 1987 4x4 LE from Colorado to Vermont and I lost (or never had it in the first place) the bolt that secures the pivot end of the alternator bracket (shown below). Does anyone have any specs on the length, threads, etc so I can pick up a replacement? Thanks!

[highwind]

Don't drive it anymore or turn it on. That also connects to you wP

[NickP]

Hello,

I'm in a bit of jam as this same bolt is completely missing on my van. I discovered this while trying to adjust the alternator and the pivot end of the bracket was just dangling. Does anyone know where I can find the part number or dimensions? I'm thinking it might be either 91611-60830 or 91611-60865. I'm afraid to drive it anywhere until can replace it so any help is greatly appreicated. Thanks!

[SpaceToaster]

The van's been running great, put 8k miles on it since my engine restoration project.

One small hiccup here lately, while driving across country my alternator adjustment bolt snapped off (dont even have the pieces, just opened the engine after it was running rough one day and it was gone), which is causing for poor tension on the belts and Im hesitant to even want to drive it until its back in place.

Im having zero luck finding the part or the part number.

Anyone in the know about where to get one?
This is the bolt with the wing nut connecting to the small square box on top front of the alternator.

[originalkwyjibo]

If you are referring to the one that passes through the block and threads into the alternator and you want one from Toyota it looks like the part number is 91611-60840. Otherwise I believe it's an M8 x 1.25 and I would try to get a 8.8 grade. Just measure the length you need and you should be able to get one at any auto parts or hardware store and don't forget the lock washer. My daughter over tightened this one and broke it off when she was helping me do the head gasket at 11 yo so don't crank it down too tight. The torque spec on this is only in the 10-15 ft lb range. A word of caution, this is not a belt to be messing around with any questionable repairs since it's the same one that drives the water pump. If it fails or comes off or even slips excessively it could cause the van to overheat in short order.91611-60840

-60840

91611-60840
91611-60840
91611-60840

[spacecruisers]

I read some similar forum posts and I think I just need some individualized advice.

I bought this van recently [...]
While inspecting I also noticed this loose wing nut bolt thing by one of the belts and alternator (and that the belt had a crack in it which i hadn't noticed when i bought it. ) I'm a little peeved as the kid i bought it from had a dad who owned an auto shop so i assumed it had been taken care of - fluids check regularly, problems fixed etc.

[originalkwyjibo]

The wing bolt is your alterntor/water pump belt tension adjuster. You are missing a bolt that should go through the block on the end of the wing bolt, through the alternator adjuster bracket, and thread into the ear on the top of the alternator. To adjust the belt, the missing bolt would be loosened and then the wing bolt turned until proper tension is achieved at which point the missing bolt would be retightened. There's also another bolt under the alternator that it pivots on that may need to be temporarily loosened during belt adjustment.

[JDM VANMAN]

i would not trust anything the PO has told you [...]. Looks like from the picture of the alternator and just the issue with the bolt missing the Van has been neglected a little.

But then again this my assumption and speculation and by no means trying to bash anyone.

Others have chimed in on some very good info so I'm just adding in my 2¢ of some of the things I've read when I was having some extensive work done on my 4x4 Van when I first got it.

Also here's some pictures of the alternator bolt your inquiring about 12x2 sorry in don't know the thread size-