New Master Brake Cylinder - Bench bleeding?

[Mike K]

I've just completed a major revamp of the brake system on my 280SL.
Installed- new calipers, new brake pads, new lines, braided stainless steel hoses, new discs and new hand brake shoes.

I used this pressure bleeder to bleed the brakes: http://www.amazon.co.uk/Sealey-VS820-Clutch-Bleeding-System-x/dp/B000ROARTI/ref=sr_1_1?ie=UTF8&qid=1439464429&sr=8-1&keywords=sealey+pressure+bleeder
A really nifty piece of kit, highly recommended, makes bleeding the brakes a simple 1 man task!

As an after-thought, seeing that I've renewed everything I also decided to replace the Master Brake Cylinder, I think the car still has the original one installed...
While I was redoing the brakes, I removed the old/existing MBC and flushed it etc. reinstalled on the car without bench bleeding, and then pressure bled the whole system twice to be sure.
The brakes are perfect, but for complete peace of mind I'm going to still install a new MBC.

My question- Even though I didn't bench bleed the old MBC, should I bench bleed the new MBC prior to installing on the car?

I've read somewhere that if you're using a pressure bleeder it's not necessary...?

As always, input is much appreciated.

Thanks and best,

Mike

[Mike K]

No feedback on this from anyone?

For what it's worth I thought I would try bench bleeding the new Master brake Cylinder prior to installing on the car. I also wanted to check if it's worth the effort. As mentioned above, I never did the bench bleeding when I removed and cleaned the old MBC. In that instance, there was a fair amount of air that came out when I pressure bled the brakes.

I made a bench bleeding kit using a syringe, clear plastic tubing, some brake line on which I made a DIN flare and added a brake nut which fits the ports on the MBC.
Placed the new MBC in a vise, fitted the fluid reservoir, filled it 1/2 way and plugged 2 of the 3 ports on the MBC with plastic nuts.
Filled the syringe with brake fluid and fastened the nut into the unplugged port. Squeezing the fluid from the syringe pushed out the air trapped in the MBC, once the air bubbles in the reservoir stopped, I plugged the port and moved on to the next 2 ports. When this was done I plugged all the ports and installed on the car.

Once all was installed I bled the brakes with the pressure bleeder.  This time, after bench bleeding the MBC prior to installation on the car, there was noticeably less air in the system.

I guess I've answered my own question- bench bleeding the MBC prior to installation on the car = much less air in the system and saves a lot of time and effort when you get around to bleeding the brakes.

The syringe method is also a better alternative to what I've seen people do, for instance using a big Phillips screw driver to pump the piston of the MBC.

Best,

Mike

[Pinder]

Not done it on my 280SL but will do as soon as i get the engine running. I did this on my 67 Buick riviera and it seems like a good idea to do it on the bench. I used a cheap kit from Napa that had a little bottle and some hoses and fittings.