Brake bleed hose internal diamater

[AotearoaMan]

Slowly getting through my long list of jobs on my new to me Jazz.

Anyone know what type of hose and the internal diamater I need for changing the brake fluid?

[Lord Voltermore]

I always used  ordinary clear pvc pipe of the type sold in diy stores. You can see  the flow, ,sometimes the colour changing from old fluid to new, and any air bubbles.  The fluid is not under any great pressure, and the pipe wont dissolve in the short time it will be in use.     

Its  a while since I last did it.  I think I used 6mm id  ,but cant be sure.   Either measure the nipple, or just familiarise yourself  with its size  . With a variety of pipe sizes on display the correct one may  be obvious.  Or buy some  of each. It can be useful for other projects.         Better still buy a couple of replacement nipples  , in case any get mangled during the job, and take one  of these with you.   

[culzean]

My MityVac brake bleeder came with 6.2mm ID x 9.5mm OD tube ( MityVac made in USA so it is imperial it is 1/4" x 3/8" ) which is a thicker wall than the normal 6mm ID x 8mm OD  tube that is popular size. I think the thinner wall stuff may well flatten a bit at full vacuum... If not using vacuum the 6 x 8 mm will be fine ( it may actually be fine with vacuum, I have never tried it ).  It is almost impossible to stop air being sucked in around the thread of nipple - but the bubbles come around the thread and then get sucked straight back out - they do not go into the brake cylinder and as long as vacuum still present when you tighten the nipple it is fine - to reduce the amount of air I have in the past put PTFE plumbers thread tape around the thread, the actual nipples seal on the taper bit on the end so the tape is not doing any harm,  and will make nipples a lot less likely to seize on corroded thread..  I like the MityVac because the collection bottle is just a bit smaller than a normal fully topped up ( to top of neck ) brake fluid reservoir,  so when the bottle getting full it is time to release vacuum and refill the reservoir,  for extra safety put some tape or permanent marker 10 to 15mm from top of collector bottle - because if you suck air into an ABS brake system you are going to need a laptop with special software plugged into system to open the valves in ABS block to get the air back out - so be very careful or things can get very complicated and expensive.  Bleeding an ABS system is really no different to older systems until you let air get in... I always suck old fluid out of reservoir and top up to the top of neck with fresh fluid before starting on the wheels, then do the two front wheels ( front offside closest to reservoir first ) and move to rear,  finishing off with rear nearside ( furthest from reservoir ) last.

[AotearoaMan]

Thanks for all the help. It takes me over an hour round trip to get to my nearest DIY store so would rather buy online where I can.  I've gone with 6mm ID which hopefully should do the job.

I'll be careful to make sure I don't introduce air into the system. It looks like the sequence for bleeding the Jazz in the service manual is:

1-Front left
2 - Front right
3 - Rear right
4 - Rear left

Hopefully the old bleed screws loosen without a fight.

[embee]

I always use a hexagon tool on bleed nipples, either a hex socket or I have a set of hexagon ring spanners. I never use bi-hex (12 point) sockets or ring spanners, and God forbid going near them with open ended spanners, they will invariably round off a small size bleed nipple if it's tight/rusted, and once they round off you are potentially in several sorts of grief that you will regret.

Culzean's system is exactly what I do, right down to the Mityvac. 

[Lord Voltermore]

I havnt done it since pre ABS days, and used an old  gunsons easybleed kit.  . By coincidence I only threw this away a couple of months ago. (pipes and seals were getting  too old)   And me too.  Not sure I would want to tackle ABS brakes these days. 

[culzean]

I havnt done it since pre ABS days, and used an old  gunsons easybleed kit.  . By coincidence I only threw this away a couple of months ago. (pipes and seals were getting  too old)   And me too.  Not sure I would want to tackle ABS brakes these days. 

It is easy-peasy with MityVac... I had a Gunson kit years ago but while it had screw caps adaptors for reservoirs like Vauxhall etc I could never find an adaptor for the Honda / Japanese 1/4 turn cap. I tried the flat bit with foam seal and the knobbly elastic chain that looped under master cylinder and was supposed to form a leakproof seal, but all I ever got was an engine bay full of brake fluid.    Got the MityVac and never looked back - it is a real one-man job with MityVac and you control everything from the hand pump.   They do a cheaper vacuum only kit, or a more expensive pressure and vacuum kit.

Silverline pressure and vacuum

https://www.amazon.co.uk/Mityvac-MV8500-Silverline-Pres-Metal/dp/B0002SQYUA

vacuum only

https://www.amazon.co.uk/Mityvac-MV8000-Test-kit/dp/B00265M9SS

[embee]

The other thing to be aware of with the vacuum type systems (Mityvac and others) is that you will almost certainly get air being drawn into the bleed hose through the nipple threads. This does not matter!

Since it is a steady flow of fluid from the brake system out of the nipple (which is what makes it very effective at getting any air out of the system) air CANNOT get back into the system due to the pressure difference, air will not flow against the pressure difference, it will only go into the bleed hose.
I used to try to get the threads to seal more effectively, but it really doesn't matter and makes not one jot of difference. Just pump the vacuum in the bottle, crack open the nipple, keep pumping to maintain a vacuum and thus fluid flow, when enough has been bled out close the nipple while there is still a vac and still flow coming out and you can't go wrong.
Just NEVER let the reservoir get low!!

[Jocko]

Just wetting the nipple thread with brake fluid helps, if you are worried about it.