Anyone know the thread/size of front caliper mount bolts?

[BTF/PTM]

I'm gonna give the z some fresh calipers since I have no idea if/when they've ever been rebuilt or replaced and in my opinion it's cheap insurance ($80 for the pair from Napa). Does anyone know what type the mount bolts are? As with the seat belts, it makes good sense to update the mounting hardware for safety reasons as well. Thanks

[webdawg1]

12mm x 1.25 x 40mm

webdawg1

[Oiluj]

Remember bolt grade is another factor. If I recall correctly, caliper mount bolts are typically metric grade 10.9.

Perhaps one of the other members can confirm this to be the correct grade?

[oldhemi]

I don't ever consider replacing caliper mounting bolts. They are pretty stout units and should be in good shape. Some parts dont need to replaced for "just because" reasons.

But, if you must, make sure that you get the quality of the original bolts - prolly from Nissan. I dont know the original hardness quality number. Just my 2 centavos.

[Arne]

I can't recall for certain, but I don't think those bolts are normal high grade bolts. I think they have full diameter non-threaded shanks to prevent the caliper from moving under braking loads. If you feel that you need to replace them (probably not necessary if they are in good condition, IMO), I'd strongly recommend only using factory bolts, not generic high grade bolts. The part number is 41250-E4100. Looks like list price is around $2.50 each.

[BTF/PTM]

Fair enough, thanks as usual for the feedback. I'll check with a local Nissan place tomorrow to see if they're available. If it costs $10 to put fresh factory-grade bolts in place I'll go ahead with it as a peace-of-mind thing.

[Oiluj]

I agree with Arne. If OEM bolts are available, go with them over generic bolts.

If not, he is also correct that you need to use partially threaded bolts. Also, a flanged hex head is usually used in this type of application.

[BTF/PTM]

Also as a side question, but still related to the work, is it safe for someone to sit inside the car while it's up on four jack stands and pump the pedal? I've never bled brakes with a car completely up on stands before. I may end up investing in a MityVac if I can't find a helper.

[Oiluj]

If it's properly supported in the correct locations, on a solid, level surface so there is no movement, it's OK to sit in the car. Done it many times with my wife in the car while I'm at the wheels. The extra weight of one person doesn't make a difference.

However, being a "belt & suspenders" kind of guy, I usually also leave the floor jack engaged under the diff or front crossmember, on whichever end of the car I'm working on.

[BTF/PTM]

The car is on a level concrete garage floor, 2 jack stands under the front frame rails just behind where they start to arc up toward the firewall and 2 jack stands under the outermost corners of the rear cross beam to which the differential front cross member bolts. I've got a piece of wood under each jack stand head, too, to help spread the weight of the "Y" shape of the stand heads. I don't think she's gonna move

The local Nissan dealership wants $5.25 each for the caliper bolts and of course only three of them are on hand. I'll see how they look when they come out, if they're beat up I'll order new ones.

[BTF/PTM]

Just as a final comment, another local Nissan dealer had a fourth caliper bolt on hand so I went ahead and picked them up. Probably not necessary, but it gives me warm fuzzies so it's all ok.

To anyone who reads this later they are definitely a special-purpose bolt and definitely shouldn't be replaced with a close hardware store equivalent. The bolts are about 2/3 smooth shank, most likely due to the above-mentioned caliper motion elimination.

I also picked up a basic MityVac pump, so that should help make bleeding the system much easier. I got it at Cycle Gear, a national chain of motorcycle equipment stores. It's a simpler, plastic-bodied version of the original, but it's MityVac brand and cost me a whopping $39 bucks and will serve my hobby mechanic purposes just fine.