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Soft Brake Line "Pinned" Against Bolt

2K views 25 replies 9 participants last post by  Outshine2 
#1 ·
I have a '50 Ford Fordor that I just did a front disc conversion on over the weekend.

The kit uses calipers from a 82-91 Malibu/Monte Carlo (I believe). They are mounted with the bleed valve facing upward (which appears to be opposite factory mounting, based on the R / L stamped on each, but according to instructions - won't clear the caliper bracket otherwise).

As such, the soft line attaches to the bottom of the caliper. This runs the soft line in a spot where it is pinned/pressed tightly against the front steering arm bolt (see pic below). It is pressed against it hard enough that it indents the line.

The brakes work great, no leaks, etc., but I worry about long-term effects of having the soft hose pressed against the bolt. Either gradually rubbing through, creating a pinch point, collapsing the internals, etc.

Note that this picture, for some reason, is upside down...


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Thoughts?
 
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#2 ·
I think that's going to eventually be a problem. I'd remove the extra threads and if your worry about it loosening you can drill cotter pin the castle nut.

You could also use braided hose and AN adaptors to get the clearance you want/need. Earls makes some black hoses that look good mimicking the factory black hose if that's a concern for you.
 
#3 ·
1) Vibration WILL eventually cause the hose to rub on the threads of that bolt and become damaged. You can slide a protective sleeve over it, which would fix the problem.

2) The RWD Monte/Malibu and other G-body cars were only built through the 1988 model year, however those "metric" calipers were used on many other cars, like Impalas and even S-10s.

3) The bleeder screws ALWAYS need to be oriented up. If they aren't, you won't be able to get all the air out.
 
#4 ·
Thanks all. Looks like I'll certainly need to correct the situation.

Related question - I was surprised to see castle nuts on both 1/2 bolts holding the steering arm to the spindle plate, as I thought those were used in primarily low-torque applications.

I've seen install instructions for other disc brake kits (same application) that replace these factory castle nuts/bolt/cotter pins with grade 8 bolts and lock nuts. Would that be sufficient? I'd think Ford originally used castle on purpose...

I'm thinking, at the least, I'll either cut the excess threads off of the existing bolt, or go with new grade 8 hardware of the proper length. Maybe new lines if I still don't have enough clearance around the bolt after that.
 
#5 ·
Pretty much every time, aside from a few instances, the auto manufactures, I mean all them too, cater to the bottom line and if that means using a castle nut to save $0.001 I'm sure they would have.

I'd use grade 5 stuff. It's less brittle and tougher. Grade 8 stuff is harder, but that doesn't always equate to strength. It's real obvious when you cut up bolts in the lathe which is a tougher material.
 
#8 ·
A grade 5 bolt is not tougher. This is a myth. A grade 5 bolt is made from steel rated at 120,000 psi, a grade 8 is made from chromemoly steel rated at 150,000 psi. The grade 5 bolt will bend, then break, before the grade 8 bolt will even bend. Many OE applications use grade 5 bolts on suspension parts because they are strong enough and are cheaper, not because they are better.

Since we use these parts in applications that are not tested to failure like OE parts are, we are better off using the strongest bolts possible all the time.
 
#7 ·
every time you touch the brake the caliper moves about 1/16 to 1/8 of an inch..

that is NOT acceptable.

i have a few questions... and a request... step back with the camera...

take another photo... do that on both sides..

i want to know where the bleeder screw is...

i need to see MORE..

can you supply a picture with the wheel turned to allow us to identify the caliper casting numbers..

i would also like to see where the brake hose hooks to the rest of the car.. and is it SAE threaded... or metric ... inverted flare .. bubble flare.. or any of the others.

is the banjo bolt metric thread or SAE thread..
 
#11 ·
this morning i can see clearly.. the picture is upside down..

the hose goes thru next to the spindle..

the bolt needs to be changed for a shorter bolt if possible.. or the end cut off but the nut needs to be changed to a metal locking nut.. not a nylon lock nut..
they do make them.. they are just harder to find..

i wonder if the bracket is actually threaded.. so if one was worried a thin jam nut could be used to lock the bolt in place..

i would also think that the bracket needs to come off to allow the change out of the zirc fitting to one with a 90 degree head if it will fit. . if it won't fit.. perhaps a little grinding to clearance for the angled zirc.. won't effect bracket strength . but i would think zirc fitting access could be just as easy as turning the wheel to the side.
 
#12 ·
After looking at the picture again, the bolt is not the only problem, it looks like it is also pinched between the spindle and something else. Every time the spindle turns it is going to rub on the hose. there has to be a better way to route them.
i would like to see a picture that has the whole brake setup.
 
#14 ·
Thanks all for the comments and suggestions.

Yes, the picture above is upside down. You are looking at the passenger caliper, from the front frame rail area. I'm at work now, but will try to get a better angle snap for a bigger picture.

The bracket hole for the bolt in question is not threaded.

The calipers are indeed stamped R and L, but the instructions have them installed opposite (L is on passenger, R is on driver), which does point the bleeder screw upwards. In fact, they will not install otherwise, as a nub on the caliper hits the brackets.

With the caliper in front of the wheel, I don't have any great routing options for the hose. The hard line is currently terminated on the frame on the rear side of the upper control arm mount. Perhaps I need to find a way to move that termination to the front of the control arm mount, so that the soft line wouldn't need to route through or around the wheel and suspension assembly. If I did that, I'd need a better way to connect the line to the caliper. If you can see on the pic, the caliper has a recessed area where the hose attaches, allowing the hose to only face rearward.

The calipers, I believe, are from a '85 Monte Carlo. If I recall, it's a 10mm banjo, and a 3/8-24 on the other end.
 
#15 ·
Adding to the above, my current plan of attack is (for both sides):

1) Cut the end off the bolt in question so that it is flush with the nut. I'll check to see if there is clearance then between the hose and bolt/nut.

2) Look at some braided stainless lines (as suggested above) - as they appear to be overall smaller diameter, and might buy me some extra clearance. I also understand that braided lines have much better abrasion resistance than rubber?

On that note - I've read horror stories of sub-par braided lines failing (primarily where the connectors are fastened)... any suggestions on finding a quality part, aside from one that is DOT approved?
 
#16 ·
You can turn the bolt around so the Castle nut is on the inside of the rotor and grind off the locating tabs on the caliper so you can move the hose a little further away from the bolt head. IF you didn't wanna grind on the caliper grind the head of the bolt thinner to get your clearance.
 
#18 ·
You can turn the bolt around so the Castle nut is on the inside of the rotor...
This! So simple, it might just work :) That itself should buy enough clearance to do the trick. As you mentioned, I'd rather not grind the caliper (or the bolt really - though I'm not sure if either would affect the component - don't want to take chances).

As I'm trying to work out how much clearance I'll need between the hose and bolt - when the pads eventually wear down, that shouldn't necessarily affect the orientation of the caliper on the pins, right? Assuming both pads (inner and outer) in the caliper will wear evenly, and the piston will extend to compensate for the wear. I know the caliper does shift a bit on the pins (as mentioned below) during normal operation (as mentioned above), but I shouldn't need to factor in additional shift (inward or outward) on the pins as the pads wear, right?
 
#17 ·
DOT....Pfft...who checks that anyway?

Any quality manufacturer of AN style hose and fitting will do. I like Earls personally.

The braided hose is just a higher quality nylon tubing with a on outer jacket of usually stainless braids for increase abrasion resistance. Not abrasive proof, but better than rubber hose alone.
 
#20 ·
i have a brake parts picture guide with stock brake hoses in it. but i left it up in the garage with the lambo. i will bring it home tomorrow..

here are a few options..

http://www.autozone.com/brakes-and-...duralast-brake-hose-front/120664_166223_5913/

Part Number: 77769
Alternate Part Number: H38665
Cadillac Escalade 1999 2000
88 to 99 K1500 front..


this one fits 87 to 93 mustangs.. but it has a larger hose end but that is easily adapted.. http://www.autozone.com/brakes-and-...duralast-brake-hose-front/120690_166223_5913/
78168
Alternate Part Number: H38818

both of the above should had slightly different part numbers for LEFT and RIGHT side.. i am just breezing thru the AZ listings of 1900+ brake hoses.

this comes up at the wrong angle.. http://www.autozone.com/brakes-and-...duralast-brake-hose-front/777490_166223_5913/
http://www.autozone.com/brakes-and-...duralast-brake-hose-front/777490_166223_5913/ 81 to 86 K20..

here is another maybe nots..

http://www.autozone.com/brakes-and-.../duralast-brake-hose-front/70295_166223_5913/

that is just ones from the first 500 of 1900+
 
#22 ·
this one http://www.autozone.com/brakes-and-t...4_166223_5913/ will work.You can bend the rigid part of the hose so it points any way you want as long as you do it with a bender that does not collapse the tubing.

Neither are likely to happen on the caliper but for conversation sakes when I use G8 bolts for front suspension tie rods, rear suspension links and hit other cars, fences, ruts, ditches, embankments, jumps, etc..the G8 bolt typically breaks. G5 bolts typically bend.
There are a couple things you can do to prevent breaking of the bolts. One is to use bolts long enough that the unthreaded shank of the bolt reaches nearly through both parts you are bolting together. This prevents a stress riser in the plane of the joint. This by itself will make the fastener over 20% stronger in that area. If there is too much bolt sticking through the nut, cut it off leaving at least one thread past the nut. The other thing to do is make sure you are torquing the bolt properly. Unless the bolt is properly stretched, it is more likely to break.
 
#23 · (Edited)
So I pulled the wheels and calipers off last night, and good thing I did... with the contact between the line and the bolt, the bolt had already rubbed through the outer layer of rubber on the brake line. The inner portion of the line was intact, but that was troubling with probably less than 2 miles on the setup :eek:

I chopped the bolt flush with the nut, but it's still too close for comfort with the brake line. I'm afraid with caliper movement and vibration it would eventually rub.

I'm leaning towards this: A 45 degree banjo on the caliper, pointing the line upwards to both completely clear the steering arm bolt, and directing the line through the largest opening between the upright and the spindle plate (as opposed to the bottom, as pictured, where it may pinch/rub between the upright and steering arm). Then to a braided brake line back to the hard line.

I spent alot of time on the garage floor last night trying to come up with a better routing path for the line, but, since the hard line is currently on the rear side of the wheel, and the caliper on the front, I'm going to have to go over, under, or through... the latter looks like the only feasible way to clear the suspension.

Question: The braided brake line has -3 AN female fittings on both ends. That'll mate perfectly with the - 3 AN male fitting on the banjo, but what about the 3/8-24 on the hard line? I understand that AN fittings have a specific flare, and, even if the threads match, the seal may not be correct?
 
#25 ·
Moving the caliper from a rear position to front is why they are reversed side to side now. Personally, I would move the hard line connection to the front and eliminate the hose routing thru everything to the rear. It's an easier mod that should take care of a lot of your issues. It will still require some imagineering to get a correct length hose to eliminate turning interference.
 
#26 ·
Thanks all for your help. Quick update - I ordered some braided lines from a local shop, with a 45 degree banjo, and was able to route them to the hard line without binding or rubbing, minus a bit of contact on the spindle upright at full turn.

Ultimately, I'll relocate the hard lines to the front of the wheel to simplify, but all good for now :)
 
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