Lancia Motor Club

Model Technical and Interest => Flavia => Topic started by: the.cern on 12 April, 2021, 11:13:13 AM



Title: Bleeding brakes
Post by: the.cern on 12 April, 2021, 11:13:13 AM
I have got a problem ...... it started a while ago when, out with a young lady in the Vignale, prudence suggested an emergency stop. The supposed emergency stop could best be describes more as gliding gracefully to a halt!!!! The brakes definitely needed some attention.
There were no apparent leaks in the system and the level in the master cylinder reservoir remained constant. I decided to renew the flexible hoses as part of a general inspection of the system. This revealed a seized front left caliper which was duly overhauled by PastParts, excellent service as usual.  New pads on the front (EBC Greenstuff), and the new SS hoses were installed and then came the fun of bleeding the system. My Easybleed was well past its use-by date so a new one was bought and then came the problem of attaching it to the MC, the filler cap of which is not threaded. Researching bleeding Flavia and Fulvia brakes suggested that a gravity system rather than a pressure system might be easier, so an assortment of hoses and jubilee clips and an improvised reservoir provided a head of 600mm over the two remote servo bleed nipples and in excess of 1000mm over the caliper bleed nipples ... more than adequate!!  So i poured about 100ml of brake fluid into the improvised reservoir and bled the servo, all very successful. Then to my horror I noticed brake fluid leaking out of the top of the MC reservoir ..... fluid was pouring out around the shafts of the two plungers in the reservoir which are not sealed in the top of the reservoir, there's no reason that they should be!
So I resorted to the good old two man system, though in this case it was one pensioner and a grandson!!! After pushing nearly 2 litres of fluid through the system there is still a lot of air in the system, the front left caliper and one of the servo bleed nipples just will not clear!!!
So, suggestions please. Andy


Title: Re: Bleeding brakes
Post by: BlueKSO on 12 April, 2021, 01:51:10 PM
Hi,
First I have to say I pretty much use the method described in the workshop manual with overhaul success.  Other people may achieve the same results using their own methods.
Iím assuming that the system is in good shape, flexible hoses etc.  I mention flexible hoses because the rear one can collapse internally.  Not that obvious.  I guess you know itís a split system and that the front plunger on the reservoir does the back brakes and the rear plunger the front brakes.

So, connect the bleed hose to a nipple on the slave cylinder (servo), doesnít seem to matter which one.
Keeping the fluid catch container ABOVE the level of the m/cylinder reservoir, bleed away until all air is expelled. 

Then proceed to bleed back brakes. 

REPEAT the process of bleeding the slave cylinder (servo), then bleed the front brakes. 

THEN, repeat the process of bleeding the slave cylinder (servo) making sure youíre keeping the fluid catch container above the level of the m/cylinder reservoir. 

Itís also probably a good idea to have the car level, whether on a lift or axle stands.
Yes itís a two man job, or in my case, one man with a long suffering wife.  Seems to work for me.  Good luck!

Cheers,  Peter


Title: Re: Bleeding brakes
Post by: lancianut666 on 12 April, 2021, 06:11:14 PM
Hmmm when I was a lot younger than I am now I spent several days and vast amounts of brake fluid trying to bleed the brakes on the Coupe I had to no avail. I would go for the plungers as they work a treat if in good order. On my Appia it is a one man job to bleed the brakes.
Clarkey


Title: Re: Bleeding brakes
Post by: lancialulu on 12 April, 2021, 09:25:02 PM
I always revert to two person bleeding..... And dont rush it. Air will come out the next day or so.... It could be the servo has gone defective due to lack of use and the push rod may be corroded letting in air....


Title: Re: Bleeding brakes
Post by: the.cern on 13 April, 2021, 08:27:51 AM
Thank you Peter, Clarkey and Tim, there's food for thought there and some options to try!! I will drag, well bribe, (in these enlightened times dragging is not allowed) my grandson into another session of pedal pumping and see how we get on!!!
Andy


Title: Re: Bleeding brakes
Post by: nistri on 13 April, 2021, 09:51:37 AM
I am not a Flavia owner, yet similr problems may be found occasionally on Fulvias (especially S1) as well. Assuming that all parts are OK (including innards of the master cylinder and the servo), first slacken a little bit the pipe connections on the master cylinder, put lots of rugs around the master cylnder and pump the brake so that some fluid comes out at the junctions. Rightighten the connectors. Use a manual vacuum system on each bleed nipple in turn so that fluid is aspirated into the proprietary reservoir. There are several makes on the market, all at reasonable price (amazon, eBay etc). This usually provides enough push (i.e. suction) to overcome air locks and re-establish normal brake fluid flow. Andrea


Title: Re: Bleeding brakes
Post by: lancialulu on 13 April, 2021, 12:34:10 PM
Thank you Peter, Clarkey and Tim, there's food for thought there and some options to try!! I will drag, well bribe, (in these enlightened times dragging is not allowed) my grandson into another session of pedal pumping and see how we get on!!!
Andy
Hi Andy I am sure you are aware pedal pumping is not the best, but push down - open nipple a tiny bit then when the pedal has gone to the floor shut the nipple - release the pedal wait 5 seconds and repeat. Sometimes air gets drawn in from around the nipple giving a frothy effect. What you want to see is big bubbles popping through.


Title: Re: Bleeding brakes
Post by: the.cern on 01 July, 2021, 06:58:10 PM
Hi,
First I have to say I pretty much use the method described in the workshop manual with overhaul success.  Other people may achieve the same results using their own methods.
Iím assuming that the system is in good shape, flexible hoses etc.  I mention flexible hoses because the rear one can collapse internally.  Not that obvious.  I guess you know itís a split system and that the front plunger on the reservoir does the back brakes and the rear plunger the front brakes.

So, connect the bleed hose to a nipple on the slave cylinder (servo), doesnít seem to matter which one.
Keeping the fluid catch container ABOVE the level of the m/cylinder reservoir, bleed away until all air is expelled. 

Then proceed to bleed back brakes. 

REPEAT the process of bleeding the slave cylinder (servo), then bleed the front brakes. 

THEN, repeat the process of bleeding the slave cylinder (servo) making sure youíre keeping the fluid catch container above the level of the m/cylinder reservoir. 

Itís also probably a good idea to have the car level, whether on a lift or axle stands.
Yes itís a two man job, or in my case, one man with a long suffering wife.  Seems to work for me.  Good luck!

Cheers,  Peter

Well Peter, I tried your method as you were the first to reply and, much to my absolute delight, success!!!!  Thank you so much. Having at last got 'a pedal', I decided to have a potter around the block. Flat battery!!! Not surprising after so long off the road, but a 6 hour charge and a booster battery got me going and yes, things work!! There is some fettling to do, I think a front pad (new) may be misaligned, but basically its all there!!!
Again, thank you,
                         Andy


Title: Re: Bleeding brakes
Post by: DavidLaver on 03 July, 2021, 11:08:46 AM

Brilliant news...