| [GMCnet] Brake bleeder review [message #298744] |
Wed, 06 April 2016 19:11  |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
A short time ago there was some discussion about brake bleeders, including comments about one from Phoenix Systems (2104-B) "V-5 DIY Reverse Brake and Clutch". I have been using the one from Jim Hupy with good success for some years but I have not been completely convinced I have all the air out of the six wheel reaction arm disk brakes on the Royale. So, I decided to try one of these units from Phoenix Systems. Since it works the opposite way it made sense to me that bleeding both directions just might be the ticket for getting rid of that last bit of air that always seems to be trapped somewhere in the system. The Royale uses an unloaded proportioning valve block and the stock master cylinder with the lines reversed so there is no margin for error in terms of having enough fluid reservoir capacity or pump cylinder capacity. Disk brakes require more fluid than drum brakes and the stock master cylinder has just enough capacity in the chamber that was designed to supply the front disk brakes to supply all four of the rear disk brakes on the reaction arm system while the chamber that was designed to supply the four rear drum brakes has enough capacity to supply the two larger front calipers on the 1 ton front end such as the one in the Royale.
Jim’s unit fits on top of the master cylinder and, using 10 or so PSI of air pressure pushes fluid from the master cylinder to the bleed nipple on each caliper. Using this Phoenix system you first suck some of the fluid out of each chamber in the MC, then fill the unit with fresh brake fluid (easy procedure to get all the air out), then place the suction hose into a fresh bottle of brake fluid and the outlet hose onto the bleed screw using a supplied rubber boot. Open the bleed screw and SLOWLY pump fluid from the caliper back to the MC. According to their literature (and common sense) the bubbles are pushed to the MC and vented to atmosphere. I say slowly pump fluid because their hand held pump acts just like a MC so you are pushing a non-compressible stream of brake fluid through the system and out through the MC. A hard or fast push would shoot brake fluid all over the place.
That unit is well designed, well made and works flawlessly. It is very clean and uses only a minimum of fluid. I was impressed. It is faster than Jim’s unit since you do not have to mount the MC top plate and get it tight before starting. I think Jim’s unit is better for a full system fluid change and flush since you don’t have to be concerned about overfilling the MC as you do when using the Phoenix system. But, Jim’s system always leaves some excess fluid in the garden sprayer pressure tank that has to be thrown away. The Phoenix system does not.
I really like the idea of bleeding the system both directions. That just makes good sense to me. In both of these cases there is no worry about introducing air into the system as you do with vacuum bleeder systems and there is no need to tape the bleed screw to prevent air from leaking back into the system from there. I have never had much success with gravity bleeding so I am well pleased with both Jim’s system and this system from Phoenix systems.
I read someone making a disparaging comment about the Phoenix system being “just a plastic thing” but I did not find that to be the case. I found it a well made unit that offers good value and which works well on our GMC coaches.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
glwork@mac.com
http://jerrywork.com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
| Re: [GMCnet] Brake bleeder review [message #298747 is a reply to message #298744] |
Wed, 06 April 2016 19:31  |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Jerry,
You forgot the punch line: Is your pedal higher/harder?
Ken H.
On Wed, Apr 6, 2016 at 8:11 PM, Gerald Work wrote:
> A short time ago there was some discussion about brake bleeders, including
> comments about one from Phoenix Systems (2104-B) "V-5 DIY Reverse Brake and
> Clutch". I have been using the one from Jim Hupy with good success for
> some years but I have not been completely convinced I have all the air out
> of the six wheel reaction arm disk brakes on the Royale. So, I decided to
> try one of these units from Phoenix Systems.
...
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Brake bleeder review [message #298753 is a reply to message #298744] |
Wed, 06 April 2016 23:49 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
Our systems were designed for a top down (master cylinder to wheel cylinder) bleeding procedure. Small aircraft on the other hand were designed to blead from the bottom up. The major difference in the two designs is the location of the bleeder screws and brake lines on the wheel cylinders.
On automotive top down applications the bleeders are on the top of the cylinders. This arrangement allows any air trapped in the wheel cylinders to escape during bleeding. When you force fluid in the bleeders and out the bottom lines any air accumulated in the cylinders stays in the cylinders.
It is alright to do what you are doing as long as you finish up with a top down procedure to remove any accumulated air in the wheel cylinder.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
