Brake Bleed Ford Ka MK1 - which method Gravity/Pump?

[dishman]

Preparing to do a brake bleed on the car.

Seems simple enough. This is the official workshop guide:



This is exactly what I expected.

However, I came across a few guides online that say you have to be careful with the pumping the break method and that a gravity bleed is better:

" Doing this with the bleeder open means the pedal will go all the way to the floor and this means the master cylinder piston seals are pushed all the way to the end of the bore in the cylinder. Old vehicles, where there may be lots of debris/corrosion etc along the unswept section of the bore, could damage the seals on the piston. This will make for loss of braking pressure when using the car from then on. A rebuild kit will be necessary to correct. Gravity bleeds avoid this risk"

Is this a valid concern? Especially for an 18 year old car?

 

[carmanmemoranda]

Gentle pumping of the pedal will be ok.

Don't open the bleed nipple too far and allow the pedal to travel too far.

But I'd use vacuum suction to pull the fluid through, but that needs a compressor

 

[Burnerman]

Gunsons Eezibleed......job done with ease, uses around 20psi from a wheel.
John

 

[dishman]

Gentle pumping of the pedal will be ok.

Don't open the bleed nipple too far and allow the pedal to travel too far.

But I'd use vacuum suction to pull the fluid through, but that needs a compressor

I assume something like this is just as good too. Pressurise the system and bleed as normal.

There is another page in the manual which shows this method too.

 

[Mottie]

View attachment 371839

I assume something like this is just as good too. Pressurise the system and bleed as normal.

There is another page in the manual which shows this method too.

I have one of those as well as the Gunson eezibleed. My order of preference is: 1. plain tube into a jar, 2. eezibleed and then 3. the pressurised bottle.

 

[dishman]

I assume DOT4 is plenty good enough for a car of this type/age.

 

[Burnerman]

Yep, that’s what you need.
John

 

[Belle427]

I find with the Gunson as soon as i attach a pipe to the bleed nipple to allow the fluid to drain into a bottle it struggles, remove the pipe and let it flow freely into a container and its fine, no idea why.

 

[Avocet]

Preparing to do a brake bleed on the car.

Seems simple enough. This is the official workshop guide:

View attachment 371808

This is exactly what I expected.

However, I came across a few guides online that say you have to be careful with the pumping the break method and that a gravity bleed is better:

" Doing this with the bleeder open means the pedal will go all the way to the floor and this means the master cylinder piston seals are pushed all the way to the end of the bore in the cylinder. Old vehicles, where there may be lots of debris/corrosion etc along the unswept section of the bore, could damage the seals on the piston. This will make for loss of braking pressure when using the car from then on. A rebuild kit will be necessary to correct. Gravity bleeds avoid this risk"

Is this a valid concern? Especially for an 18 year old car?

Yes, it's a concern. If the brake fluid hasn't been changed regularly, you'll get some rust forming on the inside of the master cylinder bore, (if it's a ferrous master cylinder) which could damage the lip of the foremost seal in the master cylinder, so you might get a failure of one brake circuit. If it's an aluminium one, it's less likely to happen. (The rearmost seal will always be running in the part of the bore that is swept by the front seal, so that won't suffer the same problems).

However, we maybe have to ask ourselves whether we'd be comfortable driving a car where that could happen if the piston ever travelled further than it normally does (e.g. an emergency stop)? Personally, I'd sooner find the problem (if there was going to be one) when bleeding the brakes.

 

[Harry Bloomfield]

Preparing to do a brake bleed on the car.

Seems simple enough. This is the official workshop guide:

There are three methods...

1. Pressure systems /Eesibleed.
2. Suction systems, at the nipple
3. The traditional pump the brake-peddle method.

I also used 1, with never a problem, but I have also used 2., which is a bit quicker when bleeding all four wheels. Some systems, I've read, only work well with method 2.

If the nipples are seized, don't round them off - just heat the nipple up with a blow lamp, allow to cool, then try again with a hex socket.