Brake caliper mounting bolt ceased

[grantw]

I think the lower caliper bolt is ceased and that I started to snap it off. Sprayed loads of wd40 and ordered some plus gas to try that as well. What is the best way to try and tackle this? So far my thoughts are:

- apply some heat to the bolt and spray with plus gas to try and get it to suck in
- hit hard on the top to try and knock/vibrate it loose.

What do you think the chance of me getting the bolt out without snapping it off? I've just bought centre punch, some HSS drill bits and some irwin spiral extractors, hoping I won't need to resort to these!

Also where is the best place to order small spares like new caliper bolts from?

Thanks,
Grant

 

[AndycruiserguyLomas]

First of all Grant, front or rear calliper? IMO heat is best every time but really you need proper garage equipment to be effective. You could try an Impact Driver or take it to a garage for them to loosen for a small fee. Although there are people on the forum who have taken more calipers off than me, I have never come across a caliper bolt that wouldn't undo, they do not snap easily.

Andy

 

[grantw]

Thanks Andy. It is a rear caliper.

I'll try and put some heat on and give it another shot ... hopefully it just came free quicker than I expected and i wasn't twisting the top off!. I gave it a liberal spray with WD-40 last night so hopefully that will help too.

At least if it does snap i'll have the correct equipment on the way!

 

[karl webster]

As Andy says. I have never known a Caliper bolt seize. A big breaker bar is setimes needed.When are we going to see some pics

 

[AndyCook]

i have never had any luck with the spiral extractor style tools - they always seem to snap... and then drilling them out is a right b@gger, since they are normally much harder than the original bolt that snapped

 

[frank rabbets]

The thread extractors are designed to remove a bolt whose threaded part has brocken off due to overtightening. This threaded part is loose in the main body but difficult to get a grip on. They are useless and not designed for seized threads.

Frank

 

[karl webster]

One thing to add. Make sure you use six sided sockets on everything possible.

 

[grantw]

Thanks guys.

@Karl I did have a big breaker bar on it when it 'felt' like I twisted it ... wasn't putting a super amount of effort into it so maybe it did just undo it.

@Frank thanks for the insight on that. That being the case when something is truly seized is it a drill out and re-tap job?

 

[Jon Wildsmith]

If it has started to shear then I don't think any amount of plus gas / heat etc is going to prevent it now. If it does shear off then find someone with a welder who knows what they're doing and weld a new nut on. There's a first time for everything but as others have said that's a big old bolt to shear and very unusual to do so. The danger with drilling and tapping is that you end up with a less than perfect thread on something you really don't want that to be the case.

 

[grantw]

@Karl - re pics yes I've been very slack with that. I need to get a build thread started. Pics won't be far away. I am off to Oz for 3 weeks on Saturday though ... so that will slow things down alot.

 

[grantw]

So what started all this was when I had 4 tyres put on I'm sure I noticed the right rear pads only had a mm on them and then on the way back from Somerset on the weekend it sounded like the inevitable metal on metal grind from the right rear brake. So I ordered some cheap ones of Milner (I plan to replace all four rotors and pads fairly soon with some decent ones) ready to do a quick pad change over.

Thankfully you guys were right ... it wasn't seized just in awfully tight. Had to use a 600mm breaker bar on it almost all the way out

I also told a small lie to Jon on the maintenance thread as it was the sliding pin bolt and not the mounting bolt that is giving me trouble. All is not over though I did mange to get it out this far but then it refused to budge any further ... so I'm a bit stumped as to what was stopping it but it was very solid. This is on the rear left caliper, I didn't start on the right as the left is on the 'safe' side of the road.



So with the bolt out this far and the other side removed I disconnected the brake line so I could swing it over to get to the pads ... which wait for it .... were pretty much brand new! Not a complete waste though as I'm certainly loosening/lubricating/cleaning everything up as I go along so it will be loads easier next time!

I"ll tackle the right noisy side tomorrow night ... I'm hoping that I do find some very worn pads as I'm sure I remember seeing ... but also don't want to find them as what kind of previous owner would replace just one side with new pads?!

@Karl this is the only pic I have so far.


Thanks for reading

 

[karl webster]

It would make more sence being the bolt you talk about. Like you said undoing and freeing up is all good. Next time should be fine.

The truck looks nice Grant


Looking forward to the mods and the build thread.


Karl

 

[grantw]

Thanks Karl

 

[AndyCook]

nice work getting it undone without shearing!
i would take the sliding pins out and clean them up and grease them
but not with copper slip (looks like the bolt has some copper slip on it in the photo?)

does the sliding pin go into a rubber boot like it does on the colorado rear calliper?
sometimes good to replace these as well if they are crudded up
and use a grease designed to go with rubber

 

[adrianr]

Red rubber grease i find best for the slide pins

whilst in the caliper area its worth having a good clean around the boot around the piston, lift it up and clean underneath make sure piston sliding freely and then stick a load of red rubber grease around the piston, under the seal and a smear inside the exposed side of the piston as well. i use a small medial syringe (without the needle!) for getting the grease under the rubber boot.

The brakes seem to need a fair bit of love and regular pm to keep them in tip top shape, especially if you venture into the mucky stuff.

 

[grantw]

Thanks guys.

The copper grease was already in there .... that is bad as it eats the rubber?

Any tips on getting the sliding pin out? It was stuck very solid ... even when putting a spanner underneath and giving it a tap with a hammer it didn't want to budge!

Once both sliding pins are out the pads should come out fairly easily or are there more tricks?

 

[grantw]

@Andy the sliding pin does have a rubber boot (well one ... with one missing?) between the upper and lower caliper parts.

 

[Jon Wildsmith]

The slide pin sits in a rubber sleeve inside the caliper (as well as the more visible external rubber bellows) and without a bit of regular TLC gets a bit stiff. A common mistake is to use copper slip on the pins which makes it 10 times worse because it attacks the rubber. When you turn the bolt out like you did, while the threaded part is engaged it is forced out by the action of undoing it. Once it gets as far out as in your picture it's held in (very firmly sometimes) by friction and vacuum. I find the best way to get it out from there is using a big screwdriver or chisel tap under the head, turn a bit, hit it again and eventually it comes free. The caliper needs to slide smoothly with not too much force required to work properly. You might be able to rescue the rubber but if it's had copper slip in it I wouldn't recommend it. Really you'll need a tub of red grease and rebuild kit which has all new rubbers. The slide pins will probably polish up ok if you put some effort into it I have rebuild kits, slide pins and shields in at the moment if you get stuck

 

[grantw]

Thanks Jon - just what I needed to hear. I may be hitting you up for those rebuild kits in the near future. The list of things to buy keeps getting longer every day.

 

[Chris]

Got to say that looking at that, the boot is probably toast. One more way to attack this is to go in at the front of the caliper and push the pin out. The pins sit in a tube (top and bottom) that goes right the way through the caliper. One has a rubber boot that goes right through and the other has a short boot and a plug. I have no idea why they don't both have the same boot. Makes little sense. On the bottom one, you can pick the plug out with a screwdriver. That gets you to the end of the pin, but the top one.. well in your case as it's stuffed, you could just rip the end off. You'd be able to push a drift in there then and give it a tap square on.

It's a weird set up and I can think of much better ways to have designed it. Metal pin sliding in a rubber sleeve? Hmm, marriage made in heaven. Not.

Be prepared to clean and replace the lot. I use red rubber grease but I think that something more soapy like the stuff used to seat bushes might be better. Be very careful when fitting the new sleeves, they rip very easily and then you can trap them as you refit the caliper. Jon, if you can get that as a part - just the long tube and singe bellows, I'd have a couple of pairs myself.

Chris

Chris