#($*@! brake hoses and flare nuts—ideas?

leapdragon · Post by **leapdragon** » 15 Aug 2021, 12:56

Hi all,

Just got done replacing rotors + pads all around BUT I need new brake hoses. As luck would have it, I have a full set. From my last V70XC, which is now retired, and on which I never managed to finish the replace-hoses job, for the same reason that I did not get it done today.

It is the one thing I have wanted to do but have NEVER yet been able to successfully do on a V70: replace the brake hoses. Today again I gave it a shot, but those lines will not budge, bracket-side. I can get them out of the caliper side, no problem.

I did not go so far as to round the nuts off today as I have done in the past. The flare wrench, though (I have tried yet another brand) is once again stretched out. Have been putting penetrant on them for a week in advance. No dice. Those damnable flare nuts on the brackets do . not . move.

I haven't yet used a blowtorch, but I have been told that it is a bad idea to take a blowtorch to any part of the brake system.

Has anyone managed to complete this job on jack stands at home? I think the last time I asked here the answer I got was that standard practice is simply to cut the metal lines, re-create the flare at metal line end, cut old nut off of the bracket with a small cutting wheel, then re-mount the lot to the bracket. For each wheel.

Short of doing that (which does not fill me with happiness), does anyone have any tricks or tips?

Post by **volvolugnut** » 15 Aug 2021, 13:21

I have successfully replaced brake hoses on my 2001 V70 at about 190K miles. Mine did not have excessive corrosion on the parts. I used SK flare wrenches. They are thick and rigid. As I recall, one end of the connection is effectively locked from rotation by the bracket (the steel tube end I think). On these connections, I like to fit the wrenches with about 30 degrees between the two wrenches so I can squeeze the wrenches together to loosen and not have to apply counter torque to hold.
I see no danger to using a moderate amount of heat as long as you flush the brake fluid afterwards. Do not burn through the hose and start a fire.
volvolugnut

Post by **MoVolvos** » 15 Aug 2021, 13:24

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Try two pairs of vise grips. When I replaced all 4 lines on the 03 S80 T6 the fronts seemed straight forward while the rear had some space limitations making more work / time.

The set for your car looks similar to the P2 S80. I think Eric The Car Guy is in the practice of cutting the hose and using a closed end wrench. Could also try a small pipe wrench for grip.

https://www.fcpeuro.com/products/volvo- ... kt#fitment

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leapdragon · Post by **leapdragon** » 15 Aug 2021, 14:14

Thanks guys, you've given me some new things to try (and hope). This weekend is now winding down but another weekend lies ahead. Let's see if I can finally get this job done!

Post by **jonesg** » 15 Aug 2021, 19:31

You can try heat treating the flare wrenches, harden then temper to reduce brittleness....see youtube.
But I think the problem is lack of mass.

I have some flare wrenches that cannot open up, they only grab the nut on one side and pull it around.
I've never had these not work unless the line binds up and twists but the nut still unthreads.
I've asked on tool forums what they're called and they just say flare wrench, but they're obviously different from the typical design.
Never been able to source them.

Post by **cn90** » 15 Aug 2021, 21:58

- Cut the old brake hose near the connection bracket, this way heated fluid can escape.

- A good trick to prevent fluid loss: measure a wood stick long enough to depress the brake pedal halfway down (wedge it against the steering wheel using a towel on the wood stick to prevent marring of the SW finish). When the brake pedal is pressed halfway down, the brake fluid will stop dripping.

- Now you can heat the connection and undo it.

- Doing a flare in situ is NOT fun, it is doable but I'd avoid it...

- This thread on the P80 platform has some good info...

DIY: Flaring your Brake Lines
viewtopic.php?t=32317

Post by **abscate** » 16 Aug 2021, 05:04

Take the caliper off and heat the joint for one minute with propane. There is no reason not to use heat on brake lines. Lift the line off the bracket so you don’t melt wires or holders during this process.

Once you commit to flaring, these lines no longer rule your life and bring you angst, as you just cut out the nasty bits and put in nice bits

It’s perfectly safe to put flares in brake lines. Add a protocol to your inspection under hood to mark your brake fluid level and inspect Daily, then weekly, then monthly. Any change dictates an inspection of the joint.

jkatz · Post by **jkatz** » 16 Aug 2021, 06:06

I have replaced the hoses in a couple of my cars, and I plan to do it this weekend too.

I always heat the fittings with a propane torch, it allows them to twist apart without any struggle. I hold a card of sheet metal behind the fitting to contain the flame and prevent anything else melting. It’s just 10 or 15 seconds of heat, just enough to expand the female side. Hold the sheet metal with a pair of pliers! Don’t heat the steel hose, it’s plastic coated to stave off rust.

Did you notice the female side of the hose seats in a 12-point hex bracket that prevents it from spinning while you twist the male half of that fitting? This means you can’t remove it by turning the female fitting, you have to turn the male end on the steel line side. I find the male flare fitting is often frozen to the steel tube, so rather than cut the steel line I twist the off the caliper from the male end of the rubber hose, then compress the leaf springs that hold the hose to the bracket and push the female side out of the wrench-like bracket and spin the entire rubber hose off.

If you decide to flare-your-own, get this kind of tool and not the old-school bars-and-clamp-needs-three-hands type:
https://www.amazon.com/Titan-Tools-5153 ... 06XPRVCPV/

I’m a disinterested linker. I have made many useless double flares with my old grizzly tool, but never a bad one with this version.

Post by **abscate** » 17 Aug 2021, 01:41

Just remember to put the nut on, the right way , before you flare.

You Can bend brake line around any smooth round object of the target bend diameter, no need for the fancy benders they will try have you on.

Post by **jonesg** » 17 Aug 2021, 12:22

abscate wrote: ↑17 Aug 2021, 01:41 Just remember to put the nut on, the right way , before you flare.

You Can bend brake line around any smooth round object of the target bend diameter, no need for the fancy benders they will try have you on.

nicop line bends easier than a coat hanger. I just run it like wiring, no pre bending needed.