Front brake system ?s.

[QBS]

There are two small holes inside the mastercylinder reservoir.  Is it possible to fill the hydraulic system from the bottom up by forcing fluid into the caliper via its bleed valve and them up into the M/C reservoir through one of the two small holes?  Maybe holding the brake lever against the hand grip would open one of the holes and allow fluid from below to fill the reservoir.

[akvision]

I always thought the system was one way when you squeezed the handle.  Then reliefed it's self when the lever was let loose.  So, therefore so goes the thinking that if the lever is reliefed the fluid would flow up and back.

But , the question begs, Why and what purpose would you accomplish?

[QBS]

I'm in the process of installing SS brakes on my '83 an am trying to figure out the easiest, most sure fire way to refill the system without resorting to spending $ on a Speed Bleeder, Myti Vac, or some such other device.

[Rick G]

A mighty vac is only about 30.00 bucks and is a very worth wile investment. I find it a necessity for bleeding brakes.

[akvision]

How about just installing the line and normal bleeding process.  If you don't want to waste fluid, disconnect at the reservoir then replace the line and fill the line up to the reservoir with a hypo unit, tap all the air out and connect to reservoir and bleed ??? ??? ???

I think, I would stay with my first line of advice and see what the manual say's.

[QBS]

I'm thinking that I'll leave both lines loose at the M/C and then use a syringe to fill the calipers and lines up through the caliper bleeder valves.  When I see fluid at the M/C I'll tighten the M/C banjo bolt, fill the reservoir and then bleed as usual using the M/C to pump fluid and any trapped air out of the calipers.

[The Prophet of Doom]

Vacuum systems are great because they suck fluid faster than lose air bubles can rise to the top.

You can make a vacuum bleeder out of an old curry jar.  Punch two holes in the top.  Run one clear plastic hosefrom the caliper right to the bottom of the jar.  Put enough fluid in the jar to cover the bottom of the caliper hose.  Run a second line from the top of the jar to your household vacuum cleaner (don't let the fluid get up to this hose or you will be sucking fluid).  Don't tape it on just seal it roughly with your hands -

Crack the nipple open, Turn on the vacuum and seal with your hands it will suck fluid through.  Job done in 3 minutes flat.  Make sure you don't drain the master cyl or you need to start again.  It's easiest done with two people.

If you keep getting more and more air, you probably need to seal your nipple threads with some plumbers tape.

[Ron_McCoy]

Filling from the calipers with a syringe works just fine. Supervision turned me on to that method and that's how I do it now.

[QBS]

Geetings Ron.  Long time no hear from.

I filled the systems (two separate ss lines, one for each caliper) up through their caliper bleeder valves.  In spite of what I posted earlier, I did it with the M/C banjo bolt tightened.  I woke up yesterday morning with the epiphany that of course the system can be filled from the bottom up, because that's basically what happens when the caliper pistons are pushed into the caliper body during the brake pad change procedure.  All the fluid behind the piston is moved upward through the line and into the M/C reservoir.

I emptied the M/C reservoir and forced brake fluid into the caliper through the open bleeder valve.  Soon, a few bubbles and a little foam appeared out of the small hole fartherest from the brake lever.  Then there was a small geyser of brake fluid squirtting of the hole. I reduced the fluid input pressure and continued filling until the reservoir was half full, at which time no more air could be seen coming from the hole.  The bleeder valve was then closed, the reservoir was emptied, and the process done again for the other line.