Topic: Replacing brake hoses - 500 - first timer questions

[Chachi]

I need to replace brake hoses on my 72 500. I have the shop manual which has bleeding information, but I am unclear about the order of steps to replace hoses.

-Do I disconnect old hoses first then connect new and then follow bleeding instructions? Or do I 'drain the lines' first before disconnecting old hoses?

-For parts in addition to hoses, I need to replace crush washers? Do I need to do new bolts too or just washers? Looks like I have 3 bolts and 6 washers (two washer per bolt).

-Does it make any difference in what is involved if I only replace the upper hose vs. both upper and lower? I ask because my hoses are actually only a year old (rubber), but the upper hose is way too long. It's 21" and I now have 400f bars on. So if for some reason if I was to only replace the upper hose and it cut out some labor I would just do that and replace with a proper length rubber hose. If it's the same amount of work either way, I'll replace everything with SS braided from Slingshot.

Also, this is my first time doing this and I will most likely be doing it solo, so any and all tips are appreciated.

Thanks.

[bryanj]

Do not drain the system and keep thw master "wet" all the time and bleeding will be easier

[Chachi]

Should I expect any fluid leaking when I disconnect hoses? Just keep M/C full like it is?

[TwoTired]

Should I expect any fluid leaking when I disconnect hoses? Just keep M/C full like it is?

Fluid will leak out anywhere there is a break in the containment vessel, which includes all the hoses and fittings.

I suck the fluid out with a Mity vac.  Which is also useful for sucking the air out of the system during brake system bleeding.

You may wish to look at the brake FAQ.

[Chachi]

I checked the brake FAQ, but I couldn't find any info regarding procedures for swapping hoses. Most discussions I've found focused on bleeding methods. I'm looking for: do 'this' in 'this order' to swap your hoses and THEN proceed to your bleeding method of choice. And keep in mind (if it's not obvious) this is my first go at it. Thanks.

[mono]

i always bleed/drain/vacuum the lines 1st.   

1.brake fluid is messy and destructive, and only lands on the worst places it can land.
2.brake fluid is very very inexpensive.
3.bleeding the bubbles out is not that hard.  just get an el cheapo bleeder kit to connect to the bleeder valve (nipple), and you can get the bubbles out in about 15 minutes.
4.new lines deserve new fluid!

[bryanj]

The most common problem with bleeding is getting the master to start pumping fluid, which is why i said keep it "wet" I.E. fluid in it.

[mono]

The most common problem with bleeding is getting the master to start pumping fluid, which is why i said keep it "wet" I.E. fluid in it.

+1. Good point.   

Sent from my SPH-L710 using Tapatalk 2

[Chachi]

Thanks guys. I talked to my buddy today who has experience doing this on his 750. I think with his hands-on info plus your replies I will be good to go handling this one. Now I just need to decide if I want to replace just my upper with a shorter rubber or swap both to SS braided. Thanks again.

[greenjeans]

Good choice on the hoses from Slingshot - I have used him several times always with good results.    You'll like the stainless braided hoses vs your originals.... you should notice a bit of difference in the level feel.

[Viktor.J]

yesterday I dissembled my whole front brake system and Therefor removed both brake lines, "light contact" and also the MC ( whole assembly without the hoses). Do I need to have brake fluid in it ? or can I store it on the shelf in room temperature ?

//Viktor

[Toxic]

Pay attention to Mono's advice #1.

Cover everything you don't want to get fluid on.  Wrap your tank and any other painted parts in plastic or better yet remove them.

The FAQ has lots of great advise.

[bryanj]

Viktor, if you are going to re-build the master -- no, if it is already empty -- no. Only worth keeping fluid in for a short time whilst working on the system like changing a hose or cleaning caliper.

If totaly rebuilt i have posted many times on how to get the master started