Hi, I need to replace my rear discs, I tried last summer at the side of the road, but couldn't loosen the blasted carrier bolts.

I still need to do this job, and I can't afford to pay a garage to do the whole job, so I was thinking of asking locally if anyone with a lift could just crack/loosen the bolt and then nip them back up, so I could take it home and do the job on the drive.

So my question is, can the carrier bolts be loosened without removing the calipers if the car is up on a lift?

 

Thanks in advance.

 

Have you tried jacking car up. Then using another trolley jack on your rachet/bar to crack it open. I did this once worked a treat when someone suggested this out of the box thinking. 

2 hours ago, gav_is_con said:

Have you tried jacking car up. Then using another trolley jack on your rachet/bar to crack it open. I did this once worked a treat when someone suggested this out of the box thinking. 

Hi, thanks for the comment, I have read that thread, and might end up having to try that if this fails. But this feels like a safer alternative, I did the fronts no problem with a 60" bar, the jack thing just sounds a bit dangerous with the car on axel stands, but I do get it.

Trust me it should not get to the stage where the car is being lifted by you using the jack on your wrench. If so stop immediately when you feel that happening. Otherwise borrow an impact wench cordless/corded. I did that once, drove to my mechanic with it’s the front caliper sticking to release the front carrier bolt, made it look so easy with that tool. 

4 hours ago, gav_is_con said:

Have you tried jacking car up. Then using another trolley jack on your rachet/bar to crack it open. I did this once worked a treat when someone suggested this out of the box thinking. 

 

That is the wrong way to do it and potentially dangerous dependant on what is holding the vehicle up, if access allows then a downward turning moment will always exert more force, fine in theory but the real problem is how little force one can apply while lying on ones back, getting it up on a vehicle lift is the best way and once again a mechanic with any nouse will pull downwards not just for safety but because he can exert more force that way, second best is a decent impact wrench, one that actually does something rather than making noise and vibration, I have used air impact wrenches for 40 years, I have one really good one, the others feel and sound like they are doing something but fail.

 

In the last year I have spent a lot upgrading and extending my Bosch 18v cordless tools and also batteries, in many ways the battery is more important than the tool for high loading jobs, the 1/2" impact driver with a genuine Bosch 5ah battery (not the other Chinese copies that are at best 3ah despite their claims) is way better than my air impact wrench even a Snap-On one, it removed 45 year old rusted trailer spring shackle bolts that would have sheared were I to have tried with my breaker bar.