Torque specs for Caliper halves bolts
 

I’ve researched everywhere on this site, the fsm and even g37 and it seems nobody knows the oem torque spec for the 4 17mm and 4 14mm bolts that hold the front and rear calipers together. So my question is for those of you that have rebuilt the calipers before what did you torque it too so it wouldn’t leak?

If you know the size (you already have that) and grade of the bolts, you can look it up in torque charts on the 'Net.

I looked up how to tell the bolt grade and it doesn’t have any marking on the top so I assume it’s a grade 2? But when I went to look up the torque specs for a 17mm grade 2 bolt I was very confused which one to look at to say the least lol

I'd try taking one of the bolts to a hardware store or machine shop to get it IDed.

Edit: My guess is that it is Grade 5. But I'm no expert. If it's zinc-plated, it's probably Grade 2.

Edit: Discovered that metric bolts use a different rating system that I am not familiar with. You need to get help from someone else.

The specs are not in the manual anywhere. What I did was to measure the diameter of the bolt shaft. Not what wrench will fit the head.

Here's a list of metric bolt torques and how to find out which grade. Nissan doesn't always mark their bolt head as for grade.

https://www.swtc.edu/Ag_Power/diesel...e%20values.pdf

This is information is not hard to find, as posted in response to your OP. It has been also been discussed on this forum before...

http://www.the370z.com/brakes-suspen...per-bolts.html

So I measured the bolt the front are M12 and the rear are M10 I can’t measure the pitch cause I don’t have the tool or know how too lol just used a YouTube video to figure out how to get the diameter lmao. I have no idea how to tell the grade though, based on the link you gave which grade would the bolt fall into? I’m a novice at this but I’m trying to learn as much as I can.

Yeah I saw that, but Idk the grade of the bolt and since rusty said that Nissan sometimes doesn’t put the markings for the grade I’ll never be able to guess it lol. Plus the link he sent and that thread and the one on this one give different torque numbers. Rusty since you’ve done it before do you remember how much torque you put on them ?

Found my notes. The 10mm was 40 ftlbs, and the 12 was 70 ftlbs. The heads have no markings on them to tell what they are. So I went with a spec in the middle. When you reassemble the halves. Take a honing stone with oil and stone the mating surfaces of each half. This will remove any high spots. The o-ring in between the halves. Make sure you put brake assemble lube or brake fluid on it before bolting the halves together.

I wish I could give you endless rep !! Thank you so so much rusty! Alright I’ll look up how to do all that and go buy the stone, I read on another thread that you said to use some blue liquid, I’ll find it again and use that to see the high and low spots.

The liquid is Hi-Spot Paste. Put a little bit on a folded paper towel and spread on one half. You need a very fine film on it. Bolt the halves together and torque to spec. Un bolt and look at the half that you didn't coat. You should see the transfer of the paste. 100% is great. But don't think you will get that. Long as you have full transfer around the o-ring. You will be good.

If you get the paste on your fingers. GOOD LUCK on getting it off. :rofl2:

The stone to get is one of those knife sharping stones that is about 2" wide and about 6" long. Spray it and the half with WD40. And work back and forth. Keeping everything wet. Any high spots in the metal will look like bright shiny areas. If you have any. Keep stoning. But be careful on the edges. You don't want to round off the edges. Keep the stone flat at all times. It's an art.

https://www.mscdirect.com/product/details/00264101

Man I’m a terrible artist but good thing there’s YouTube nowadays 😂. Okay I get what you mean, I’m confident in doing it myself now with all the information you’ve given! If I have any problems I’ll shoot you a dm if you don’t mind haha. Thanks again for all the info and help ! :tiphat:

You may have to stone, clean, bolt together, stone, clean, bolt together a couple of times. On mine, I got about 75% contact all over. Around the o-ring hole, It was 100%.

If you don't like the idea of using a whet rock, get a large, flat plate (metal works best) and lay some wet/dry sandpaper on it. Place caliper half on sandpaper and go to town. Use plenty of water/oil/etc.

Use a very fine sandpaper. Start off with 800 grit. Glass plate is the best.