BMW R65/R100 Restoration - Part 7 - Brake Caliper Rebuild

Greetings friends,

This is a continuation of my series of posts documenting the restoration of my BMW R65. For the previous post in this series, click here.

I bought a Brembo brake caliper (sort of) sight unseen on Ebay. The "unseen" portion of this purchase was the condition of the inside of the caliper, as well as no part numbers being provided, only that this caliper was the correct vintage for BMW airheads. For $40, I really couldn't pass on the price and took a chance on it...

When it arrived, I was amazed at how nice the caliper was, and after opening it up I found almost no corrosion or other significant signs of wear! I hit the jackpot but decided the rebuild the caliper anyway, primarily due to the fact that I can only assumer all the seals and gaskets are 40+ years old and need replacement anyway.

Brembo provides a huge selection of repair and rebuild kits for their brakes, and I was pleased to find the exact kits I needed for this specific caliper. The caliper didn't come with the retaining pins and spring for the pads, so I had to buy those separately. The seal kit came with piston gaskets and dust covers as well as replacement bolts for holding the halves of the caliper together. I'll go into more detail below.

Cleaning the interior of the caliper was an easy process, like I said there wasn't much corrosion at all, and the surfaces just had old brake fluid on them. A thorough wiping with acetone and paper towels cleaned them right up. Some acetone-soaked Q-tips were able to reach into the small holes and remove any build-up.

The Brembo kits included some assembly lubricant which was much more viscous than brake fluid but it made the re-assembly a breeze. In a matter of about 15 minutes I installed the piston seals, dust covers, and bolted the two halves of the caliper back together. A small O-ring is sandwiched between the halves of the caliper to connect the brake fluid galleys, so both halves of the caliper receive fluid. When torqueing the big bolts holding the caliper together, I mounted the caliper back onto the forks which gave me the leverage I needed, as the torque spec for these bolts is 50 ft-lb. 

The brake pads have alignment pins as well as a retaining spring, which may look a bit clumsy in the photo below, but once around the brake rotor will be aligned well. At this point the reassembly is complete, I just need to reinstall the caliper onto the forks and bleed it with new fluid!

I hope to be able to make more posts soon for this project. Life has been busy and this project has been on the backburner, but I pretty much have most parts in place to at least have the bike moving... just gotta type out a lot more of these updates. Keep an eye out for more posts!

Thanks for reading,

Juju

Moto Guzzi Breva 750 - Head Guards

 Greetings friends,

I have a few upgrades I plan to make for my Breva 750 and in this post I'm sharing one of them: head guards! I purchased these on Ebay from a seller from the UK, the link to his Ebay page can be found here. The head guards are very well made and I find the engraved MG eagles quite snazzy looking! Their function is to protect the spark plugs from breaking in the event of dropping the bike since the spark plug is the first part of the bike that would contact the ground in that scenario. This is unfortunately the nature of Moto Guzzis due to the design and position of the engine & cylinders,  and with a broken plug, you're stuck... The guards are designed such that the spark plugs can still be removed and replaced as needed.

I filmed a short video of me installing the guards, which I've uploaded to Youtube and can be viewed below.

I also took some 'glamour' shots of the head guards using a nicer camera, the best of which you can see below. I'm really pleased that the guards are not only functional but very good-looking as well!

Thanks for reading,

Juju

Moto Guzzi Breva 750 - Oil Change Torques

 Greetings friends,

After my first year as a motorcyclist, I decided it was time to upgrade to a larger and more comfortable bike. I recently sold my 2002 Yamaha Virago 250 and bought a far more appropriately-sized 2004 Moto Guzzi Breva V750ie.

Being a newcomer to the Moto Guzzi community, I've quickly realized that resources (for parts as well as information) for these motorcycles are very limited in the USA. There are several MG-dedicated forums, but often if I'm searching for information on Google, the forum results are hard to navigate. In an effort to add to the limited library of english-language resources for Moto Guzzis, I will be documenting what I learn as I perform routine maintenance or repairs on this bike during my ownership.

Although oil changes are simple matters, a few bits of info I was never able to get a clear answer for were the torque specifications for the two oil drain bolts as well as for the oil filter bolt. Additionally, the gearbox and bevel drive require annual (or 5000mi) oil changes, and the torque values for these bolts are equally unclear. I will share here the torque values I've found to work for all these drain bolts as well as any peculiarities I observe in the oil change procedure.

A Guzzi enthusiast located in Australia, Mike, has many useful videos carrying out maintenance on the Breva 750, so I won't go into any detail about how to perform these oil changes. If you wish to view the relevant videos, they can be found here for the engine oil, and here for the bevel drive and gearbox. Mike's instructions are very thorough, but he unfortunately mentions nothing about torque for any of the fasteners he removes/reinstalls. Here are the torque values I use:

Torque Specifications:

Engine:

    Oil Pan Front Drain Bolt: 20 ft-lb (~27 N-m)

    Oil Pan Rear Drain Bolt: 15 ft-lb (~20 N-m)

    Oil Filter Bolt: 10 ft-lb (~13 N-m)

Gearbox:

    Drain Bolt: 15 ft-lb (~20 N-m)

    Fill/Level Bolt: 20 ft-lb (~27 N-m)

Bevel Drive:

    Drain Bolt: 15 ft-lb (~20 N-m)

    Fill/Level Bolt: 10 ft-lb (~13 N-m)

I figured out another trick after having some trouble with the crush washer for the engine oil drain bolt. The washer supplied with my new filter kit was made of aluminum, and too large for the M10 drain bolt, so it sealed poorly and resulted in a minor oil leak. I'm including pictures of it below, to show how it not only poorly seated, but that also the head of the bolt began digging into the non-sealing side of the washer as well. I had a similar sealing issue with a copper crush washer, so I decided to buy some Dowty-type sealing washers, which have bonded rubber on the inside, which provide an excellent seal that doesn't leak oil at all!

It's pretty obvious in these photos how a small section near the bottom of the washer wasn't sealing, and how the bolt head was digging into the washer, likely not helping the sealing issue. The Dowty washer solves this problem providing a perfect seal.

Thanks for reading,

Juju