Front brake caliper mounting bolts question (1 Viewer)

[AFei]

Long story short: My LX470 had difficult moving forward while on the trail and the brake pedal feeling was strange. Turned out the front passenger side brake caliper lost one mounting bolt and the other bolt was sheared. Checked the driver side, and both bolts were loosing. It was clear that the loosing bolt caused the problem.

While reviewing the service manual, I noticed there should be a washer but my LX didn't have it. Checked a brunch of YT videos, and didn't see any has the washer either.

So my 1st question is if the washer is necessary? I assume it's since it's designed in that way. Can I use any M14 washer, or it's a special one?

The 2nd question is if thread-lock has to be used to secure these 2 mounting bolts? Any particular thread-lock? The service manual didn't mention it...

 

[GrouchyTech]

I’ve never seen a caliper come loose if it was properly torqued in the first place. There’s always the remote possibility but I suspect they weren’t installed correctly in the first place. Go ahead and check all your caliper/pad hardware and make sure everything is correct there before proceeding.

Replace the bolts and washers, the washer isn’t really “special” but it is supposed to be there. They aren’t captive to the bolt so they’re easy for the average person to misplace. If the threads in the caliper are fine and the holes in the mount are still intact and weren’t damaged then just reinstall everything and torque to 90 lb/ft. Feel free to add some blue thread locker, but it isn’t necessary.

 

[GrouchyTech]

Here are the part numbers for the bolt and washer.
Bolt: 90105-12175
Washer: 90201-12452

 

[Hokie LX]

I'd say get new OEM bolts and washers and use some blue locktite. I had the caliper bolts back out on an 80 I was driving down the highway from OKC to LA a few years ago and it was almost a bad situation. I replace the bolts whenever the calipers come off now. They're cheap and it's good insurance.

Bolts: 90105-12175
Washers: 90201-12452

 

[AFei]

I'd say get new OEM bolts and washers and use some blue locktite. I had the caliper bolts back out on an 80 I was driving down the highway from OKC to LA a few years ago and it was almost a bad situation. I replace the bolts whenever the calipers come off now. They're cheap and it's good insurance.

Bolts: 90105-12175
Washers: 90201-12452

Yeah, just bought the bolts from the dealer. However, when I asked for the washer, the part guy said they never ever sold any of them . Guess will have to just ask them for the particular part number.

 

[OGBeno]

90105-12175 do **not** require washers.

Washers were only specified through 08/1999. After that build date, caliper washers were not required.

 

[AFei]

I’ve never seen a caliper come loose if it was properly torqued in the first place. There’s always the remote possibility but I suspect they weren’t installed correctly in the first place. Go ahead and check all your caliper/pad hardware and make sure everything is correct there before proceeding.

Replace the bolts and washers, the washer isn’t really “special” but it is supposed to be there. They aren’t captive to the bolt so they’re easy for the average person to misplace. If the threads in the caliper are fine and the holes in the mount are still intact and weren’t damaged then just reinstall everything and torque to 90 lb/ft. Feel free to add some blue thread locker, but it isn’t necessary.

Somehow I didn't see your response earlier today. Weird...

The LX just received new Toyota front pads and rotors 200 miles ago. It ran pretty smooth, and no vibration or noise. Pretty sure it was torqued to 90. Anyway, just re-torqued the driver side back to 90 lb-ft. For the passenger side which was in trouble, just got the broken bolt out from the spindle. The caliper seems still in good shape. However, it did need a new cylinder boot. One brake pad (new under 200 miles) was damaged, and had to buy another set of 4 to replace it. Hope will have the 25% off promotion soon...

 

[AFei]

90105-12175 do **not** require washers.

Washers were only specified through 08/1999. After that build date, caliper washers were not required.

View attachment 3691639



View attachment 3691640

Good catch! Guess that's why no one mentioned that washer at all...

Just checked the parts catalog for 1999 LX470, and the bolt part # is 90101-12144, which has regular hex head instead of hex flange head. Although washer isn't required for flange head, I will still add the washer to be safe...

 

[GrouchyTech]

The LX just received new Toyota front pads and rotors 200 miles ago.

That was my concern. Somebody spun them in, but they weren’t torqued. If it was a shop then they need to be informed. People DO make mistakes but this mistake is critical and somebody needs to alter their technique. Personally, if it’s safety critical I’ll put a wrench on the bolt immediately after it’s threaded in. Then it gets marked in pink paint marker. I don’t leave that fastener to do anything at all before that is accomplished. Because I was in the same predicament long ago, somebody brought it to my attention, and I altered my routine.

…..Were you the “shop?”

 

[OGBeno]

Good catch! Guess that's why no one mentioned that washer at all...

Just checked the parts catalog for 1999 LX470, and the bolt part # is 90101-12144, which has regular hex head instead of hex flange head. Although washer isn't required for flange head, I will still add the washer to be safe...

View attachment 3691765

View attachment 3691766

Don’t add a washer.

 

[ClassyJalopy]

Listen to @OGBeno and don't add a washer.
I have had them back out once before. Since then I always get new bolts each time and put some blue locktite on the threads and then torque to the specs.

 

[AFei]

Don’t add a washer.

Listen to @OGBeno and don't add a washer.
I have had them back out once before. Since then I always get new bolts each time and put some blue locktite on the threads and then torque to the specs.

Got it! Removed the washer but adding blue locktite.

Thanks for the recommendation.

 

[2001LC]

As @OGBeno said; washer was done away with, after 99. We use the newer bolt on all years 90105-12175, when we replace.

The rear calipers, do use a washer 90201-12452 with bolt 90101-12167.

Toyota changed the recommendation in 2008 (200 series). Making the bolts non reusable. The new bolts are the same as 100 series, except they have sealer on threads, and torqued reduce 20% (due to lube/sealer).

It's likely, Toyota was seeing to many issue with reusing caliper bolts.
I'm now adding medium thread seal, always. I also, mark with paint, each bolt after torquing in.

Brake Caliper mounting bolts! Replace them when removed. Alert Alert Alert

forum.ih8mud.com

 

[AFei]

As @OGBeno said; washer was done away with, after 99. We use the newer bolt on all years 90105-12175, when we replace.

The rear calipers, do use a washer 90201-12452 with bolt 90101-12167.

Toyota changed the recommendation in 2008 (200 series). Making the bolts non reusable. The new bolts are the same as 100 series, except they have sealer on threads, and torqued reduce 20% (due to lube/sealer).

It's likely, Toyota was seeing to many issue with reusing caliper bolts.
I'm now adding medium thread seal, always. I also, mark with paint, each bolt after torquing in.

Brake Caliper mounting bolts! Replace them when removed. Alert Alert Alert

forum.ih8mud.com

Wish I have seen your post earlier before the brake job.
This is another sample only following FSM is not enough.