Builds New project, 1969 fj40 (4 Viewers)
- Thread starter 6f40j9
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
6f40j9
SILVER Star
- Thread starter
- #542
On the left is the bolt(s) that came with the water pump a couple years ago, from a well known cruiser ‘store’. On the right is the bolt(s) that came in the ‘OEM Water Pump Bolt kit for ‘74 and earlier Land Cruiser FJ40; from a different well known cruiser store. (They’re the same length.)
Then the pic of how much is exposed, to go into the block.
I get what y’all are saying about them needing more engagement, but this is apparently factory.
Then the pic of how much is exposed, to go into the block.
I get what y’all are saying about them needing more engagement, but this is apparently factory.
pb4ugo
SILVER Star
What's the condition of the threads at that depth? Are the new bolts sloppy at that depth? Does the bolt engagement get better deeper in the hole?
Last edited:
6f40j9
SILVER Star
- Thread starter
- #544
Two of the ‘short bolt’ holes were fine, as was the long one. I can thread a bolt in the ‘bad hole’ by hand farther in than it goes when bolting up the water pump, but for some reason the threads on the bolt get messed up when bolting the water pump on.
I’m waiting on a bottoming tap or whatever it’s called to clean the bad threads (they’re fine with my tapered tap) and try again.
They all held for a year and a half, the bad one just started leaking the last time I started it up.
Power wash the grit/crud out of the hole with carb/brake clean/ WD40. Then use a good lube on the tap I like AnchorLube.
A thread restorer and a bottoming tap are two totally different tools. Taps cut threads, restorers will clean existing threads and "push" any distorted thread back into place. This is if your block holes have some minor damage. If it's just dirt in the hole, a wire brush, brake clean, and compressed air is all you need. If the restorer won't thread in, you may need to use a tap to cut the first few threads clean. I would not bottom a tap out in that hole, you will have a poor fit.
As far as the bolts go, the shortest stock bolts are 35mm in length. There is also a longer bolt listed on the parts diagram, appears to be 10mm longer. Since the face of the block where the pump mounts is a flat plane, the water pump casting is where the length variance comes from. When attached, each bolt is at the same depth in the block. You can easily gauge the depth of the block holes by using a bit of wire, brake cleaner straw, etc. The bolts you have, with the water pump you have, are insufficient. Measure the thickness of the water pump where the thru holes are, add 15 mm, and add the thickness of your spring washer. This is approximately the bolt length you need, at a minimum. Now measure the depth of the block holes, the thickness of the water pump at the thru hole of interest, add the thickness of the spring washer, this number is the maximum length of your bolts.
If you have half the thread engagement that's required, at the specified torque, your doubling (plus) the stress on the threaded connection. By using a bolt length to better match the hole depth (threaded grip) you're spreading the stress evenly across the gripped parts.
As far as the bolts go, the shortest stock bolts are 35mm in length. There is also a longer bolt listed on the parts diagram, appears to be 10mm longer. Since the face of the block where the pump mounts is a flat plane, the water pump casting is where the length variance comes from. When attached, each bolt is at the same depth in the block. You can easily gauge the depth of the block holes by using a bit of wire, brake cleaner straw, etc. The bolts you have, with the water pump you have, are insufficient. Measure the thickness of the water pump where the thru holes are, add 15 mm, and add the thickness of your spring washer. This is approximately the bolt length you need, at a minimum. Now measure the depth of the block holes, the thickness of the water pump at the thru hole of interest, add the thickness of the spring washer, this number is the maximum length of your bolts.
If you have half the thread engagement that's required, at the specified torque, your doubling (plus) the stress on the threaded connection. By using a bolt length to better match the hole depth (threaded grip) you're spreading the stress evenly across the gripped parts.
What water pump brand are you running? I've ran into some wild fitment issues with aftermarket junk. I won't name any names, cool cruisers of... Could it be the casting of your pump is thicker than stock?
firemanj92
SILVER Star
I think GMB (from Japan not China) was an OEM water pump supplier for earlier LC's.
best water pump? - https://forum.ih8mud.com/threads/best-water-pump.1312709/
tag @ToyotaMatt
best water pump? - https://forum.ih8mud.com/threads/best-water-pump.1312709/
tag @ToyotaMatt
6f40j9
SILVER Star
- Thread starter
- #558
Started on the running boards. Had to grind the heads off the screws, then drill them out and got a little aggressive on a couple. 
Then I ground off some of the larger rust spots on the boards and painted them with oshpo.
Got rid of more of the horrible black spray paint too.
Then I ground off some of the larger rust spots on the boards and painted them with oshpo.
Got rid of more of the horrible black spray paint too.
