I'm working on daughters new (to her, 21 year old) Honda motorbike.
She would normally do it (under my supervision) but Covid etc etc.

I've done the chain and sprockets (un-seizing the rear brake in the
process) and today replaced the fork seals and dust covers and in the
process, found the front brake caliper to be pretty stiff (single
sided floating caliper with dual pistons) so currently have it on the
bench with some Plus Gas round the pistons.

Now in the past I have forced the pistons out with compressed air
(restricting their travel with suitable blocks of wood / rag / clamps
etc) but feel it would be better to do hydraulically because it would
be more predictable and possibly safer.

So I might hook it back up to the bikes front brake system this time
but I was wondering about rigging up a general purpose hydraulic hand
pump for when I need to do such things.

It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

Cheers, T i m

On 25/10/2020 22:07, T i m wrote:
I'm working on daughters new (to her, 21 year old) Honda motorbike.
She would normally do it (under my supervision) but Covid etc etc.

I've done the chain and sprockets (un-seizing the rear brake in the
process) and today replaced the fork seals and dust covers and in the
process, found the front brake caliper to be pretty stiff (single
sided floating caliper with dual pistons) so currently have it on the
bench with some Plus Gas round the pistons.

Now in the past I have forced the pistons out with compressed air
(restricting their travel with suitable blocks of wood / rag / clamps
etc) but feel it would be better to do hydraulically because it would
be more predictable and possibly safer.

So I might hook it back up to the bikes front brake system this time
but I was wondering about rigging up a general purpose hydraulic hand
pump for when I need to do such things.

It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

Cheers, T i m

Given that you already have a hydraulic pump with all the right fittings
and fluid to hand this seems like a lot of work.

If you are going to make a general purpose system you have a choice
between using mineral oil and "brake fluid". (When you say "hydraulic
fluid" earlier it is not quite clear what you mean). I would generally
use mineral oil (absorbs less water, gives better lubrication for a
stuck or rusted system, and less likely to strip paint). But, you might
then worry about compatibility with seals specified for brake fluid. No
problem if you are going to replace them once you get the thing apart.
In fact in general people worry more than is necessary about
compatibility of mineral oil with rubbers other than nitrile and viton.
Provided the exposure is short and it is cleaned off well with suitable
solvents there should not be a problem. Although mineral oil will cause
natural and many other rubbers to swell and become soft the effect is
generally reversible.

On 25/10/2020 22:29:55, newshound wrote:
On 25/10/2020 22:07, T i m wrote:
I'm working on daughters new (to her, 21 year old) Honda motorbike.
She would normally do it (under my supervision) but Covid etc etc.

I've done the chain and sprockets (un-seizing the rear brake in the
process) and today replaced the fork seals and dust covers and in the
process, found the front brake caliper to be pretty stiff (single
sided floating caliper with dual pistons) so currently have it on the
bench with some Plus Gas round the pistons.

Now in the past I have forced the pistons out with compressed air
(restricting their travel with suitable blocks of wood / rag / clamps
etc) but feel it would be better to do hydraulically because it would
be more predictable and possibly safer.

So I might hook it back up to the bikes front brake system this time
but I was wondering about rigging up a general purpose hydraulic hand
pump for when I need to do such things.

It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

Cheers, T i m

Given that you already have a hydraulic pump with all the right fittings
and fluid to hand this seems like a lot of work.

+1, that was my very thought. If it was a commercial business doing
loads then I can see the advantage.

On Sun, 25 Oct 2020 22:29:55 +0000, newshound
wrote:

snip

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.


Given that you already have a hydraulic pump with all the right fittings
and fluid to hand this seems like a lot of work.

Well true, it's just that I'll have to do that with the caliper
dangling on the bike and with risk of spraying brake fluid everywhere
rather than on the bench in the workshop. ;-)

If you are going to make a general purpose system you have a choice
between using mineral oil and "brake fluid". (When you say "hydraulic
fluid" earlier it is not quite clear what you mean).

Jack oil? I saw a litre of something like that when looking for fork
oil yesterday but will have a closer look at it today.

I would generally
use mineral oil (absorbs less water, gives better lubrication for a
stuck or rusted system, and less likely to strip paint).

Yup, they seem to be the properties I'm looking for.

But, you might
then worry about compatibility with seals specified for brake fluid. No
problem if you are going to replace them once you get the thing apart.

Good point and true.

In fact in general people worry more than is necessary about
compatibility of mineral oil with rubbers other than nitrile and viton.
Provided the exposure is short and it is cleaned off well with suitable
solvents there should not be a problem.

As would be the case (brake cleaner).

Although mineral oil will cause
natural and many other rubbers to swell and become soft the effect is
generally reversible.

OK, thanks.

I appreciate Tribology is your thing g but do you have any
experience of any diy-able fittings that can takes the sorts of
pressure you might find in such a system?

Cheers, T i m

On 26/10/2020 08:48, T i m wrote:


I appreciate Tribology is your thing g but do you have any
experience of any diy-able fittings that can takes the sorts of
pressure you might find in such a system?

Cheers, T i m

I've never DIY'd hydraulics apart from flaring brake pipe (easy enough
with the right tools) or buying and fitting ready made commercial hoses.
In another life a colleague of mine used to recharge Citroen suspension
spheres (I'm not sure what pressure they ran at). Another poster gave a
link for DIY hose terminations that looked quite interesting. Since I
replaced my tractor with an ATV I don't have any hydraulic kit except on
the cars and vans (and I only touch those in emergencies).

On Mon, 26 Oct 2020 14:05:47 +0000, newshound
wrote:

On 26/10/2020 08:48, T i m wrote:


I appreciate Tribology is your thing g but do you have any
experience of any diy-able fittings that can takes the sorts of
pressure you might find in such a system?


I've never DIY'd hydraulics apart from flaring brake pipe (easy enough
with the right tools)

Noted.

or buying and fitting ready made commercial hoses.

Ok.

In another life a colleague of mine used to recharge Citroen suspension
spheres (I'm not sure what pressure they ran at). Another poster gave a
link for DIY hose terminations that looked quite interesting.

Yeah, I will follow those up, when I get the pressure testing gadget
thing.

Since I
replaced my tractor with an ATV I don't have any hydraulic kit except on
the cars and vans (and I only touch those in emergencies).

Understood. ;-)

Cheers, T i m

p.s. Whatabout what difference it might make if I put 5W oil in a
motorcycle fork as opposed to the recommended 10W?

I ask because one of the issues that most people suffer on motorbikes
is 'dive' under braking and unless your bike is fitted with any 'anti
dive' solutions (one of mine is), I don't think going between most of
the std weight oils used in such roles would impact that much (given
how much the suspension has to move 'normally' to give a reasonably
smooth ride)?

On 26/10/2020 14:14, T i m wrote:
On Mon, 26 Oct 2020 14:05:47 +0000, newshound
wrote:

On 26/10/2020 08:48, T i m wrote:


I appreciate Tribology is your thing g but do you have any
experience of any diy-able fittings that can takes the sorts of
pressure you might find in such a system?


I've never DIY'd hydraulics apart from flaring brake pipe (easy enough
with the right tools)

Noted.

or buying and fitting ready made commercial hoses.

Ok.

In another life a colleague of mine used to recharge Citroen suspension
spheres (I'm not sure what pressure they ran at). Another poster gave a
link for DIY hose terminations that looked quite interesting.

Yeah, I will follow those up, when I get the pressure testing gadget
thing.

Since I
replaced my tractor with an ATV I don't have any hydraulic kit except on
the cars and vans (and I only touch those in emergencies).

Understood. ;-)

Cheers, T i m

p.s. Whatabout what difference it might make if I put 5W oil in a
motorcycle fork as opposed to the recommended 10W?

I ask because one of the issues that most people suffer on motorbikes
is 'dive' under braking and unless your bike is fitted with any 'anti
dive' solutions (one of mine is), I don't think going between most of
the std weight oils used in such roles would impact that much (given
how much the suspension has to move 'normally' to give a reasonably
smooth ride)?

The one anti-dive system I had that really worked was on an MZ 250 with
a leading link fork. The torque reaction on the shoe carrier plate
(can't remember the proper name for it) made a huge difference. Contrast
that with the Aerial Leader / Arrow with their trailing link suspension,
I'm convinced that even with the tiny 6 inch drums the braking effect
was deliberately weakened to reduce dive.

I don't know about modern anti dive systems, is there some cleverness?
The only passive effect I can see with a telescopic fork is that the
torque reaction will increases the loads on the plain bearings. (On the
MZ you could actually feel the front lift when you braked hard).

Putting in a thinner oil will just reduce the damping a bit. But 10 to 5
is not a very big change. I know all the design theory about EHL film
thicknesses, but (within limits) gearboxes are not actually all that
sensitive to oil viscosity because a thicker oil will run a bit warmer,
and that will drop the viscosity significantly. The same is probably
true of fork oil, especially on bumpy terrain.

On 25/10/2020 22:07, T i m wrote:


So I might hook it back up to the bikes front brake system this time
but I was wondering about rigging up a general purpose hydraulic hand
pump for when I need to do such things.

It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

I still use reusable fittings for repairs, they're good up to 200bar

https://www.whitehouseproductsltd.co...ES/R010404.jpg

The ferrule has a ******* thread which you wind on the hose, there are
different types depending on whether you skive off the outer rubber
first or not or how many steal braid layers the hose has, you then wind
the coupling in and the taper grips the hose to the ferrule.

They are deprecated by the hydraulics engineers whose code of practice
does not allow them to repair hoses but only supply a new hose with new
swaged fittings.

On Sun, 25 Oct 2020 22:33:59 +0000, AJH
wrote:

snip

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

I still use reusable fittings for repairs, they're good up to 200bar

More than enough! ;-)

https://www.whitehouseproductsltd.co...ES/R010404.jpg

Thanks.

The ferrule has a ******* thread which you wind on the hose, there are
different types depending on whether you skive off the outer rubber
first or not or how many steal braid layers the hose has, you then wind
the coupling in and the taper grips the hose to the ferrule.

So no need for an outer crimp / ferrule or is there still one?

They are deprecated by the hydraulics engineers whose code of practice
does not allow them to repair hoses but only supply a new hose with new
swaged fittings.

Understood. This would only be for the odd thing like this where I
have always wanted something more powerful (than ear) and more
controlled (than air) and for £12 for the hand pump and reservoir
(plus some adaptors), I thought it was worth the cost / effort setting
something up (even this late in my life). ;-)

We currently have 7 motorcycles in various states of readiness and
several cars so there is a 'good chance' I will be able to make use of
something like this in the future (as might mates etc).

I'll have to have a measure up and see if the motorcyles tend to use
the same size banjo connector and if so, I might just need one 'tail'
(1/2" female to banjo) adaptor (and it doesn't matter if it isn't a
perfect fit, as long as I can seal it for the job).

Cheers, T i m

On 26/10/2020 09:14, T i m wrote:
On Sun, 25 Oct 2020 22:33:59 +0000, AJH
wrote:

snip

I think the pumps come with a 1/2" male (looks tapered) outlet and so
I'd need a mating female to whatever I was working on, in the case of
most motorbikes, a 'banjo' connection of some sort.

I still use reusable fittings for repairs, they're good up to 200bar

More than enough! ;-)

https://www.whitehouseproductsltd.co...ES/R010404.jpg

Thanks.

The ferrule has a ******* thread which you wind on the hose, there are
different types depending on whether you skive off the outer rubber
first or not or how many steal braid layers the hose has, you then wind
the coupling in and the taper grips the hose to the ferrule.

So no need for an outer crimp / ferrule or is there still one?

No the taper thread screwing into the ferrule which is already screwed
onto the hose with a reverse thread replaces the need for crimping.

The ferrules for one type of hose are then used with whatever end you
want, of the type in the link.

I am only saying you can use it to adapt fittings for testing, certainly
not for use in hydraulic components for brake systems of vehicles.

On Mon, 26 Oct 2020 21:04:02 +0000, AJH
wrote:
snip

The ferrule has a ******* thread which you wind on the hose, there are
different types depending on whether you skive off the outer rubber
first or not or how many steal braid layers the hose has, you then wind
the coupling in and the taper grips the hose to the ferrule.

So no need for an outer crimp / ferrule or is there still one?

No the taper thread screwing into the ferrule which is already screwed
onto the hose with a reverse thread replaces the need for crimping.

Ah, gotcha.

The ferrules for one type of hose are then used with whatever end you
want, of the type in the link.

Cool.

I am only saying you can use it to adapt fittings for testing, certainly
not for use in hydraulic components for brake systems of vehicles.

Understood ... and exactly how I would be using it (testing).

Cheers, T i m

In article ,
T i m wrote:
It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

Vehicle Wiring Products have a fair selection of auto hydraulic fittings,
pipe and tools.

--
*(over a sketch of the titanic) "The boat sank - get over it

Dave Plowman London SW
To e-mail, change noise into sound.

On Mon, 26 Oct 2020 10:29:23 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
It seems they do them fairly cheap on eBay and I'm assuming I could
use basic hydraulic fluid (less likely to take the paint off?) but I'd
need to make up some fairly high pressure adaptor hoses (25 bar)?

Is this something one can do diy and if so, do you need any special
tools for the joints etc?

Vehicle Wiring Products have a fair selection of auto hydraulic fittings,
pipe and tools.

Could be handy if I do car related stuff (and I might) so thanks.

For the moment I'm interested to consider how I might 'best' convert
whatever the fitting is that comes on the hose supplied with this pump
kit and whatever I might be trying to test.

Like, do I leave the 1/2" mal thread on there or cut it off and fit a
hydraulic quick connector of some sort (that might be more logical /
flexible. If that makes it all too expensive, the idea of screwing a
temporary fitting to the cut end of the flexi hose might be sufficient
(assuming I can get what I want in the right size in that format etc).

Cheers, T i m