I'm trying to replace my brake hoses. They're cracking and appear a bit damp from brake fluid... Not very safe.

It should be an easy job (I've replaced brake hoses on other vehicles) , but I can't seem to loosen the nut that ties the brake line to the brake hose on my GTA.

A 10mm wrench is too small. It won't fit on the nut. A 12mm wrench kind of fits, but not well. It doesn't fit snugly and as a result, I can't put much force on it at all because it will just slip over the corners of the nut.

I dug up my SAE wrenches and a 7/16 wrench is too small and the next size up that I have is a 1/2 inch. It fits even looser than the 12mm wrench.

Below is a picture of the nut I'm talking about.....

 

those flare nuts are typically 5/16 or 3/8 or 8mm or 10mm

im not sure what the oem size is.

 

Thanks, but none of those wrenches will fit properly.. They're all too small.

I'm guessing that the ideal wrench would be 10.5mm or perhaps 15/32 inch... But locally those are hard sizes to find.

Sigh.. Maybe I'll have to break out the vice grips

 

My guess and im far from an expert is it got replaced sometime in the past. I would suggest when you redo the line use a part that fits a common size. If you bugger it up getting off just use a new one thats inline with your toolset.

 

OK, thanks Jon.. I think that's what I'll be doing.

 

Just Recently Replaced Mine,It's 12MM.

 

OK.. Obviously your 12mm wrench fits.. I guess my nut has been damaged somehow.. Perhaps someone else rounded the threads and that's why my 12mm wrench won't grip properly.

Thanks for posting that photo.

 

You should be using a line wrench!!

 

i bought a brake line wrench for my 03 silverado z71 its exactly 12mm... only fits one nut and its a pain to use. took it back cuz my regular box wrenches work fine.

gta's nut looks corroded and rounded off which may be his issue

 

Corroded and rounded... that's WHY you use a line wrench!!

 

yes but it may be too late for him. worth trying though.

but it does look like the lines werent cleaned of brake fluid when it was installed last.

it doesnt sound like he rounded them off or allowed them to become corroded.

 

Just to follow up...

I managed to get the nuts off the left and right hand lines today and now have new brake hoses. The nut was wet because I coated it with penetrating oil the day before I took the photo. (I usually do that with nuts and bolts that haven't been off for many years).

I wound up making a line wrench using a thin cutting wheel on my die grinder. It worked great!