brakes Replacing Brake Hoses - Advice?

[ATLBMW]

Any tips before I start replacing the cracked rubber hoses with brand new rubber hoses? I've got the parts, now any advice?

Thanks in advance!

[Koblenz]

I used a pressure bleeder today for the first time. Would suggest that and flare wrenches.

[mikebontoft]

definitely flare wrenches. just to get the lines loose at least. you really don't want to strip a brake line fitting because then you'll have to cut off the flared line, slip over a new fitting and re-flare it. then hope you didn't cut it too short.

pressure bleeder is well worth it, ensures no air gets sucked into the system as a result of someone's "oh I thought you said to let go of the pedal!" mistake. (if you have a helper... make things very clear about how to bleed the system)

Avoid letting the master run dry as you have open brake lines.

edit: wear gloves too... brake fluid feels weird. Bugs the hell out of me.

Edited October 7, 2013 by mikebontoft

[tim385]

Yeah and it tastes horrible as well!!

[Koblenz]

BTW, the two rear hoses look to be a real PITA! I don't know what the secret  to removal is there.  Mine looked new so for now, they are new.

[02fanatic]

Yeah, but remember the inside of rubber brake lines will generally go bad long before the outside shows any signs of wear!  My '73tii still had the original lines on it until the rear brakes started to fail due to swelling inside the rear lines.  I recently replaced the brake lines on my '76 '02 with stainless steel lines, and I didn't find it at all difficult to remove the rear lines...it's just a little difficult getting in there...I should mention that I have a lift, so I'm sure it's tougher to do laying on your back! :-)

 

Don't forget the front calipers have three bleed nipples....I did....totally forgot about the one on the back side and my brakes wouldn't pump up until I bled those lines!  Thanks to this forum I bought flare wrenches....can't do this job properly without them!

 

Good Luck,

 

John

 

BTW, the two rear hoses look to be a real PITA! I don't know what the secret  to removal is there.  Mine looked new so for now, they are new.

[ray_]

Yeah and it tastes horrible as well!!

I hear it's okay with fava beans and a nice Chianti.

 

;-)

Edited October 7, 2013 by ray_koke

[mikebontoft]

not very good with chips though...

[Mike Self]

One additional trick...

 

Before loosening any of the flex hoses, take a piece of Saran wrap, put it under the brake fluid reservoir cap and then replace the cap.  It will prevent air from getting in the reservoir and will slow (but not stop) fluid from dripping out the end of the rigid line when you remove the hose. You can temporarily plug the lines on the M/C end with a golf tee.  Just don't break it off inside the line!  First loosen both ends of the hose so you know they'll unscrew without a lot of grief. 

 

To prevent excessive brake fluid loss/mess, remove the master cylinder end of the hose first and let it dangle downward onto some newspaper (keep it away from the rotor and pads) then install the new hose on that end. Now remove the caliper end of the old hose.  Lastly install the new hose on the M/C end.   After you've done all four, bleed and you're done.

 

mike

[ATLBMW]

One additional trick...

 

Before loosening any of the flex hoses, take a piece of Saran wrap, put it under the brake fluid reservoir cap and then replace the cap.  It will prevent air from getting in the reservoir and will slow (but not stop) fluid from dripping out the end of the rigid line when you remove the hose. You can temporarily plug the lines on the M/C end with a golf tee.  Just don't break it off inside the line!  First loosen both ends of the hose so you know they'll unscrew without a lot of grief. 

 

To prevent excessive brake fluid loss/mess, remove the master cylinder end of the hose first and let it dangle downward onto some newspaper (keep it away from the rotor and pads) then install the new hose on that end. Now remove the caliper end of the old hose.  Lastly install the new hose on the M/C end.   After you've done all four, bleed and you're done.

 

mike

Great tip, thank you!  My only concern in the matter now is doing the rear hoses, as it sounds like those are going to be tough to get too.  I haven't yet looked at the rear ones, but I do have my flare wrenches ready.  There was a suggestion to cut the line in the rear and use a socket, but that makes me nervous in case I am unable to get the new ones on.

 

The saran wrap and golf tee (into the hard line?) are great calls, as this is going to be messy.  My hope is that my lines are in fact the problem, because if in fact my problem is a hung caliper I will be rebleeding the brakes again after buying a rebulit caliper from BavAuto...

 

Thanks everyone - I think I will photograph this project and add it to the forum.

[mikebontoft]

have fun with it and enjoy the brakes. Note that it stains/eats paint too.

[schoir]

I just replaced the flexible rubber brake lines on my '71.  They had swelled shut on the inside, as mentioned above.

 

The rears were a real PITA because of limited access.  To increase the access, I removed the sway bar hold-down brackets and let the rear sway bar just dangle down, out of the way of the subframe.  Saved some time by not removing the sway bars entirely.

 

You will also need a small 14mm open end wrench to lock the end of the rubber hose in place (inside the back of the subframe) while you try to unscrew the flare fitting with the 11mm crow's foot wrench.  Spray some PB Blaster on the flare fitting junction and, if necessary you can also apply some heat with a heat gun to help loosen things up.

 

Regards, Maurice.

[Dev02]

I got a set of Crowfoot Ratchets (http://www.sears.com/craftsman-10-pc-metric-crowfoot-wrench-set/p-00904363000P?prdNo=1&blockNo=1&blockType=G1 no affiliation) to get mine out. I was VERY careful not to strip anything, but these did the trick for me.

 

Also, remember you are not keeping the used soft lines, so if needed you can cut them and use a deep socket to get it out, then use the mentioned methods to put the new one in.

Edited October 7, 2013 by Dev02

[ATLBMW]

Front brake hoses:

Okay, attempted to start work tonight. When I used my 14mm flare wrench to turn the hose, the hard line moved with it (I obviously didn't move it much once I realized what was happening).

Is the trick to us an 11mm flare wrench at the top near the MC end and the 14mm on the bottom near the piston end, using both wrenches at the same time, opposing each other?

[TobyB]

uh, yeah, you are trying to unthread the nut on the hardline (11mm wrench) from the socket on the flex line (14mm).

Aligning the wrenches so you can squeeze them together is usually easiest.  And you'll pinch yourself if they pop loose.

 

Once they start to move, make sure the nut on the hardline is spinning freely.  If it's rusted on, you can twist the line off.

 

hth

 

t