Help! Accidentally put Glycol in the brake system (Spitfire)

[badgerspitfire]

It was all going well, gravity bleeding the brakes after changing the coolant.  I then reached to top up the reservoir and bright green fluid came out of the bottle into the reservoir!!!! (the bottles of glycol and brake fluid looked identical).  I ran round, shut off the bleed valve (rear right) then sucked out what I could with a turkey baster.  Then I bled the rear right for ages (put about half a litre through).  Then continued to bleed each wheel in turn, more than I normally would.   The pedal feels "soft" now, it may be my imagination, or it could be some residual glycol in the system.  Grateful for any advice how to get it out.  Bleed again and put loads of fluid through?  Many thanks.  (Note to self: don't work on the car when tired / check bottles / don't be so stupid) 

[Colin Lindsay]

Just bleed it. It will have contaminated the brake fluid, but won't remain in the system, so just bleed plenty of good clean brake fluid through and it'll be none the worse. If you suspect there's some remaining, bleed again, for peace of mind. There'll be no permanent damage to anything.

[yorkshire_spam]

Sh*t happens, I topped my radiator up with 2 litres of degreaser the other day instead of nice clean water! doh!

[badgerspitfire]

31 minutes ago, yorkshire_spam said:

Sh*t happens, I topped my radiator up with 2 litres of degreaser the other day instead of nice clean water! doh!

Glad it is not just me!

[badgerspitfire]

Thanks guys! 

I ought to add that I also readjusted the rear brake shoes today too.   There were "catching" at part of the rotation (3/4 of rotation free, then grinding for last 1/4 against pads).  Could readjusting the rears have changed the pedal feel?

[NonMember]

24 minutes ago, badgerspitfire said:

Could readjusting the rears have changed the pedal feel?

Definitely. Slackening off the rear adjusters will make the pedal feel spongy.

[badgerspitfire]

1 hour ago, NonMember said:

Definitely. Slackening off the rear adjusters will make the pedal feel spongy.

Thanks.  Will tighten them back up again and see if that improves things.

[Pete Lewis]

rear shoe adjustment will affect the pedal travel there are a few things that will generate extra travel

if the hand brake cable is holding the shoes open 

if the back plate has a groove worn for the HB lever pivot 

drum run out 

rear shoes fitted upside down

to set the handbrake before you re adjust i would disconnect the cable at one wheel ,  pop the drum off and check the rear trailing shoe has the square hole (not used ) at the bottom

refit drum , fully lock up the shoe adjuster ,  now reconnect the cable to just fit the pin , not tight /not slack.

now release the adjuster to just free the wheel,  you get a better feel of free if the wheel is on ( best to jack the rear upright to a running height not let it sag /hang down

if you wish to check the back plate is not grooved you need to remove the wheel cylinder 

if the tend to be a tight/ loose as you rotate indicates some runout  this may be the drum . the hub or the drive shaft ( not so simple )

Pete

[badgerspitfire]

Many thanks for the detailed reply Pete,  I've ordered new drums and shoes (the old drums didn't look the best) and will have a go at fitting them this week.  Hopefully that will eliminate any drum issues.  I'll look at those items as I work (though I might not be brave enough to remove the cylinder - this is my first 'classic' and very much learning as I go along).

A couple of questions if that's ok:

- Does hand brake cable holding the shoes open = shoes abeing held away from the drum?

- Do I need to do the handbrake adjust procedure (disconnecting cable) for each wheel in turn?

- Does trailing shoe = the one rearmost (ie nearer the rear of the car)?  

Many thanks again.  Will rebleed for a 2nd time to make sure I am rid of the last of the glycol too.

[Colin Lindsay]

18 minutes ago, badgerspitfire said:

Many thanks for the detailed reply Pete,  I've ordered new drums and shoes (the old drums didn't look the best) and will have a go at fitting them this week.  Hopefully that will eliminate any drum issues.  I'll look at those items as I work (though I might not be brave enough to remove the cylinder - this is my first 'classic' and very much learning as I go along).

A couple of questions if that's ok:

- Does hand brake cable holding the shoes open = shoes abeing held away from the drum?

- Do I need to do the handbrake adjust procedure (disconnecting cable) for each wheel in turn?

- Does trailing shoe = the one rearmost (ie nearer the rear of the car)?  

Many thanks again.  Will rebleed for a 2nd time to make sure I am rid of the last of the glycol too.

I'll sneak in before Pete gets back:

The handbrake cable holds the shoes against the drum, so if it's on at all, it's pulling the shoes out. If it's not on the shoes are relaxed ie inwards, not touching the drum.

You can adjust each wheel if you require, but it's a single cable and unless your adjuster screws are really at their last threads on one side it's okay to adjust just one side, the handbrake when pulled will compensate for the cable adjustment and centralise it. 

The trailing shoe is the one NOT directly pulled by the handbrake so usually the rearmost one.

Here's a photo of what they should look like:

 

[NonMember]

2 minutes ago, Colin Lindsay said:

The trailing shoe is the one NOT used by the handbrake so usually the rearmost one.

That's true but not the strict definition. A "leading shoe" is one where the actuator (piston or handbrake lever) pushes the "leading" edge, i.e. the end that a point on the rotating drum hits first (when travelling forwards). Since the actuator is fitted at the top of the backplate on Spitfires and Heralds, this is the front shoe. A "trailing shoe" is the opposite.

[Colin Lindsay]

2 minutes ago, NonMember said:

That's true but not the strict definition. A "leading shoe" is one where the actuator (piston or handbrake lever) pushes the "leading" edge, i.e. the end that a point on the rotating drum hits first (when travelling forwards). Since the actuator is fitted at the top of the backplate on Spitfires and Heralds, this is the front shoe. A "trailing shoe" is the opposite.

I actually just posted an edit while you were replying; as this question concerns the handbrake it seemed the easiest way to post it, but I've amended to say that it's not the one directly acted upon by the handbrake ie the handbrake lever moves the front shoe, which then causes actions which move the rear shoe, so it's 'led' by the other and is 'trailed'... as old mechanics would say. 

Do any of our cars use the opposite ie where the rear is the leading shoe?

[badgerspitfire]

Thanks guys.  That's great info to have and  gives me confidence to tackle the job when the parts arrive, hopefully Thursday. 

While I'm doing so much bleeding of the system, is it worth trying the DOT 5 fluid (Automec) like what Rimmers sell?   I've read conflicting reports on the internet.  I was also just planning on changing it doing a massive bleed exercise, rather than much dismantling (unless I need to get inside the brake master cylinder to overhaul it - fingers crossed I don't).  The car also pulls to the right on braking.  Left caliper/disc cooler than the right side, so I'm guessing a problem front left.  Going to change the caliper (and pads discs while I'm at it) and see what that brings.  I've only got standard pads as replacement - should invest in a set of Mintex before going to that trouble? 

PS.  What happened to the car in the photo 😮!

[trigolf]

34 minutes ago, badgerspitfire said:

Thanks guys.  That's great info to have and  gives me confidence to tackle the job when the parts arrive, hopefully Thursday. 

While I'm doing so much bleeding of the system, is it worth trying the DOT 5 fluid (Automec) like what Rimmers sell?   I've read conflicting reports on the internet.  I was also just planning on changing it doing a massive bleed exercise, rather than much dismantling (unless I need to get inside the brake master cylinder to overhaul it - fingers crossed I don't).  The car also pulls to the right on braking.  Left caliper/disc cooler than the right side, so I'm guessing a problem front left.  Going to change the caliper (and pads discs while I'm at it) and see what that brings.  I've only got standard pads as replacement - should invest in a set of Mintex before going to that trouble? 

PS.  What happened to the car in the photo 😮!

Be aware, that there's two types of DOT 5 fluid, one is DOT 5 Silicon and one is not. If you decide to swap fluid types - if it were me - I would flush the entire system out with meths before refilling with Silicon. 

Gav

[Pete Lewis]

yes dot5 and dot 5.1  are vastly different fluids and dot4   never mix them 

if youre on a learning job stick to dot4 just wash any spillage with water 

Pete

[yorkshire_spam]

I have a car with dot 5 and one with dot 4. The only reason 1 has dot 5 is it's what a previous owner put in and I can't be bothered with the faff of flushing it to go back to dot 4. Unless I wanted a concours car with no risk to the paint I'd never bother with either variety of 5.

 

[badgerspitfire]

thanks chaps.  DOT 4 it is!