TheSamba.com :: View topic - Hydraulic system restoration -DOCUMENTATION & HELP requested

Thu Aug 12, 2021 5:17 pm

Hi Folks

I'm now starting to fully dig into my "Vancouver Van" Toni.
I am starting with fully dealing with the hydrolic system - checking it's health and replacing/rebuilding all the rotten or potentially rotten parts.

FIRST QUESTION: (how to remove the caliper pistons without an air gun??)
I want to first rebuild the front calipers... so my plan is to remove the calipers but keep them hooked up to the hydrolic lines. Then I intend to use the pressure of the brake pedal to pop out the pistons.
I have never done this before and would love if someone could give me a quick step by step guide as to how to do this.
One this video at 7:00 this guy does the deed... is he doing it right? (I have Early Girling calipers)

thanks
Ed

Thu Aug 12, 2021 5:35 pm

You can get a cheap air compressor for $100 (maybe less) at any big box store,
Go get one.

Dave

Thu Aug 12, 2021 7:18 pm

djkeev wrote: You can get a cheap air compressor for $100 (maybe less) at any big box store,
Go get one.

Dave

We are in the process of liquidating everything in my mom's house here, so now is not the time to buy new tools.

I know it can be done with brake pressure so this is how I'd like to do it - unless there is any specific reason why it would be a bad idea.

Thu Aug 12, 2021 8:50 pm

You can make a mess if you do not have a container under it! :D

Connect it back to the brake line and do not mount it back and step on the brake pedal!
If your doing both sides put a piece of wood in front of the pistons so they do not come out all the way, but far enough to get a grip on the pistons.
If one side comes out you will lose the brake pressure and not be able to get the other side out.

Thu Aug 12, 2021 9:48 pm

Steve M. wrote:
Connect it back to the brake line and do not mount it back and step on the brake pedal!
If your doing both sides put a piece of wood in front of the pistons so they do not come out all the way, but far enough to get a grip on the pistons.
If one side comes out you will lose the brake pressure and not be able to get the other side out.

Aha, yes that is the piece of wisdom I was looking for... we do not want them to come out ALL the way - otherwise the pedal pressure trick won't work anymore!

Good, seems a little tricky but should work I think - - - thanks!

Thu Aug 12, 2021 9:51 pm

epowell wrote: Steve M. wrote:
Connect it back to the brake line and do not mount it back and step on the brake pedal!
If your doing both sides put a piece of wood in front of the pistons so they do not come out all the way, but far enough to get a grip on the pistons.
If one side comes out you will lose the brake pressure and not be able to get the other side out.

Aha, yes that is the piece of wisdom I was looking for... we do not want them to come out ALL the way - otherwise the pedal pressure trick won't work anymore!

Good, seems a little tricky but should work I think - - - thanks!

You would have thought of it!

Thu Aug 12, 2021 9:56 pm

Steve M. wrote:

You would have thought of it!

Of course I would have >>> AFTER the first piston popped out.

Sun Aug 15, 2021 1:33 pm

I have taken a little break from the van for a few days because on my trip and thereafter I sorta pulled a muscle in my back... and have been avoiding van work (You never realise how physically demanding this work is until you have a bad back).

So my first challenge, as expected is to get those 2 19mm caliper bolts off. Of course they are stuck on there. I have a breaker bar but the tie-rods are blocking access. I am told that removing the 2 8mm allan bolts holding the UCA is a good way to get the spindle to swing forward to increase access to those caliper bolts (and others) - but I am wondering if wrenching on those bolts with the spindle hanging free might stress out the lower ball joints?

Another possibility is heat - I have a PROPANE torch here, and am thinking maybe to try that on those bolts - but don't want to melt anything in the process......

...any suggestions?
Thanks
Ed

PS - yeah, the bad back (which is healing up really fast :) ) is preventing me from utilizing my usual Herkuleon strength :D

Sun Aug 15, 2021 3:35 pm

Soak them with a 50/50 mix of ATF & acetone repeatedly. Tap the offending fastener and housing. By all means try some heat.

If you can’t fit a breaker bar, I recommend an impact wrench.

Sun Aug 15, 2021 3:38 pm

Soak them with a 50/50 mix of ATF & acetone repeatedly. Tap the offending fastener and housing. By all means try some heat.

If you can’t fit a breaker bar, I recommend an impact wrench.

Sun Aug 15, 2021 5:41 pm

Thanks!
What I found solved the access problem is to turn the steering-wheel to either extreme... this enabled getting the breaker-bar onto at least the top bolt - I didn't try the lower bolt yet.

I only have a 12-point socket, and this started to round off the head so I stopped of course, and will have to buy some 6-point sockets, and a better breaker-bar.... then continue.

I had some very good luck cracking the brake-lines free on both sides using just a box-end wrench 11mm. I have a propane torch and I carefully heated those little brake line nuts, and got them all free :) :) :)

...now to get on Craigslist to find some more tools.

Sun Aug 15, 2021 6:16 pm

Fyi- maybe change your title for future searches:
Hydraulic

Sun Aug 22, 2021 9:07 am

Hi Folks
I'm about to start digging deeper into the HYDRAULICS. First things first:
The size of the hard brake-lines is 4.75mm I'm told.... but here in Vancouver it seems I can only get IMPERIAL sizes - does anyone know what is the best most suitable size in IMPERIAL?

Also, my clutch hardline also needs replacing --- I am told that this should also be the exact same line as the brake lines, but on my my van (early diesel) the clutch line is BIGGER. Is this normal? My clutch line looks probably original. . . .
- just replace it with the same line as the brake lines?? I am also replacing the clutch master and slave cylinders.

Thanks
PS - cunifer looks really expensive from CAN TIRE, but seems pretty cheap on AMAZON.

EDIT: Just had a look and coming out of the MC are both small size lines. Coming out of the clutch MC is the larger size.

Sun Aug 22, 2021 9:17 am

A little simple arithmetic on a calculator will reveal what "inch" size matches "4.75mm".

3/16inch x 25.4mm/inch = X

solve for X

Mark

Sun Aug 22, 2021 9:22 am

crazyvwvanman wrote: A little simple arithmetic on a calculator will reveal what "inch" size matches "4.75mm".

3/16inch x 25.4mm/inch = X

solve for X

Mark

this also works http://www.worldwidemetric.com/measurements.html
so they give me 0.187"

So 0.187/1 = X/16
So multiply 0.187 X 16 = 2.992 (which is close enough to "3")
So size is 3/16" :) :) :)

Mark, do you know what the story is with the clutch line? Should I also use the 3/16" for that too, or copy the larger diameter line which is now on my van?

Thanks

Mon Aug 23, 2021 9:19 am

OK... nobody is answering but according to my research and what I actually see under my van the clutch hard line from clutch master cylinder TO slave rubber line, is a 1/4" hard line.

All other brake lines are 3/16th".

If I'm getting this wrong please let me know.

I suppose this means that the fitting for the 1/4" line are different than the fittings for the 3/8" line.

Mon Aug 23, 2021 11:46 am

REMOVING THE PISTONS USING BRAKE PEDAL PRESSURE:

So this is my plan:
- I will slowly press the pedal with calipers still on rotors, until pistons just lightly tough the rotors (pads are already removed)
- Then I'll disconnect the fluid lines (then cap them), and remove the caliper
- at this stage each piston should have 2cm protruding out, and only 1cm remaining in the bore... there will also be just over 1cm of free space in the middle... so hopefully this means that with only 1cm piston remaining in the bore it will be possible to pull it out by hand and remove it.
- of course once I remove the first one, I will lose pedal pressure completely and will need to remove all the remaining in the same way <pulling out the remaining 1cm by hand/fingers>

My hope is that getting that last 1cm out by hand will not be too difficult... BUT if I manage to get the first one out in this way, likely the remaining 3 will also be equally do-able.

Wish me luck!

Mon Aug 23, 2021 11:56 am

Luck! Thumbs up...

Mon Aug 23, 2021 12:21 pm

dobryan wrote: Luck! Thumbs up...
Moving into uncharted territory.. .. ..
so far so good, I got the pistons compressed lightly onto the rotors.
Now to disconnect the caliper, and see if I can remove those pistons by hand. . . . I don't think this is going to be easy. I also don't want to damage the pistons cuz they might still be good [however I do have 4 new ones handy].

Mon Aug 23, 2021 1:11 pm

Got the caliper out and off... but those pistons are definitely not just plopping outta there easily. I will have to put a think piece of wood between them and reconnect - then pump the pedal a little bit more.

Not sure where all of this is leading, but at least I have the calipers out, and in the worst case can just take them somewhere with a compressor.....